mi·cro·scope ( mº"kr…-sk½p") n. 1. An optical instrument that uses a lens or a combination of lenses to produce magnified images of small objects, especially of objects too small to be seen by the unaided eye. 2. An instrument, such as an electron microscope, that uses electronic or other processes to magnify objects.

re·veal 1 ( r¹-v¶l") v. tr. re·vealed re·veal·ing re·veals 1. a. To make known (something concealed or secret): revealed a confidence. b. To bring to view; show. 2. To make known by supernatural or divine means: " For the wrath of God is revealed from heaven " Romans 1:18 [Middle English revelen from Old French reveler from Latin rev¶l³rere- re- v¶l³re to cover( from v¶lum veil) ] re·veal "a·ble adj. re·veal "er n. re·veal "ment n.

Synonyms: reveal expose disclose divulge betray These verbs signify to make known what has been or ought to be kept from the knowledge of others. Reveal suggests uncovering what has been concealed: " He was glad it was to him she had revealed her secret " (Edith Wharton). To expose is to lay bare to public scrutiny: In a slip of the tongue the schemer exposed his true motivation. Disclose means to make known as if by removing a cover: The journalist refused to disclose the source of her information. Divulge often implies the improper revelation of something private or secret: " And whatsoever I shall see or hear in the course of my profession . . . if it be what should not be published abroad, I will never divulge, holding such things to be holy secrets " (Hippocratic Oath). To betray is to make known in a breach of trust or confidence: " A servant . . . betrayed their presence . . . to the Germans " (William Styron). The term can also mean to reveal against one's desire or will: Her comment betrayed annoyance.

re·veal 2 ( r¹-v¶l") n. 1. a. The part of the side of a window or door opening that is between the outer surface of a wall and the window or door frame. b. The whole side of such an opening; the jamb. 2. The framework of a motor vehicle window. [From Middle English revalen to lower from Old French revaler re- re- avaler to lower( from a val down) ( a to) (from Latin ad; See ad- ) ( val valley) ;See vale 1 ]

in·vis·i·ble ( ¹n-v¹z"…-b…l) adj. 1. Impossible to see; not visible: invisible writing. 2. Not accessible to view; hidden: mountain peaks invisible in the fog. 3. Not easily noticed or detected; inconspicuous: " The poor are politically invisible " Michael Harrington 4. Not published in financial statements: an invisible asset. n. 1. One that is invisible. in·vis "i·bil"i·ty or in·vis "i·ble·ness n. in·vis "i·bly adv.

brace ( br³s) n. 1. A device that holds or fastens two or more parts together or in place; a clamp. 2. A device, such as a supporting beam in a building or a connecting wire or rope, that steadies or holds something else erect. 3. braces Chiefly British Suspenders. 4. An orthopedic appliance used to support, align, or hold a bodily part in the correct position. 5. Often braces A dental appliance, constructed of bands and wires that is fixed to the teeth to correct irregular alignment. 6. An extremely stiff, erect posture. 7. A cause or source of renewed physical or spiritual vigor. 8. A protective pad strapped to the bow arm of an archer. 9. Nautical A rope by which a yard is swung and secured on a square-rigged ship. 10. A cranklike handle with an adjustable aperture at one end for securing and turning a bit. 11. Music A leather loop that slides to change the tension on the cord of a drum. 12. Music a. A vertical line, usually accompanied by the symbol , connecting two or more staffs. b. A set of staffs connected in this way. 13. A symbol, or , enclosing two or more lines of text or listed items to show that they are considered as a unit. 14. Mathematics Either of a pair of symbols, , used to indicate aggregation or to clarify the grouping of quantities when parentheses and square brackets have already been used. Also Called bracket . 15. pl. brace A pair of like things: three brace of partridges. See note at couple . v. braced brac·ing brac·es v. tr. 1. To furnish with a brace. 2. To support or hold steady with or as if with a brace; reinforce. 3. To prepare or position so as to be ready for impact or danger: Union members braced themselves for a confrontation with management. 4. To confront with questions or requests. 5. To increase the tension of. 6. To invigorate; stimulate: " The freshness of the September morning inspired and braced him " Thomas Hardy 7. Nautical To turn (the yards of a ship) by the braces. v. intr. 1. To get ready; make preparations.

Phrasal Verbs: brace up 1. To summon one's strength or endurance. [Middle English from Old French two arms from Latin br³cchia,pl. of br³cchiumarm from Greek brakhi½n upper arm; See mregh-u- in Indo-European Roots.V., partly from Old French bracier from Old French brace]

brac·er 1 ( br³"s…r) n. 1. One that braces, especially one that supports or holds something steady. 2. Informal A stimulating drink, especially of an alcoholic beverage.

bra·cer 2 ( br³"s…r) n. 1. An arm or wrist guard worn by archers and fencers. [Middle English probably from Anglo-Norman from Old French braceure from bras arm from Latin br³cchium;See brace ]

bract ( br²kt) n. 1. A leaflike or scalelike plant part, usually small, sometimes showy or brightly colored, and located just below a flower, a flower stalk, or an inflorescence. [From Latin bractea gold leaf perhaps from Greek brakhein to rattle] brac "te·al ( br²k"t¶-…l) adj.

crack ( kr²k) v. cracked crack·ing cracks v. intr. 1. To break or snap apart. 2. To make a sharp, snapping sound. 3. To break without complete separation of parts; fissure: The mirror cracked. 4. To change sharply in pitch or timbre, as from hoarseness or emotion. Used of the voice. 5. To break down; fail: The defendant's composure finally began to crack. 6. To have a mental or physical breakdown: cracked under the pressure. 7. To move or go rapidly: was cracking along at 70 miles an hour. 8. Chemistry To break into simpler molecules by means of heat. v. tr. 1. To cause to make a sharp, snapping sound. 2. To cause to break without complete separation of parts: cracked the glass. 3. a. To break with a sharp, snapping sound. See note at break . b. To crush (corn or wheat, for example) into small pieces. 4. To strike with a sudden, sharp sound. 5. Informal a. To break open or into: crack a safe. b. To open up for use or consumption: crack a book; cracked a beer. c. To break through (an obstacle) in order to win acceptance or acknowledgement: finally cracked the " men-only" rule at the club. 6. To discover the solution to, especially after considerable effort: crack a code. 7. To cause (the voice) to crack. 8. Informal To tell (a joke), especially on impulse or in an effective manner. 9. To cause to have a mental or physical breakdown. 10. To impair or destroy: Their rude remarks cracked his equanimity. 11. To reduce (petroleum) to simpler compounds by cracking. n. 1. A sharp, snapping sound, such as the report of a firearm. 2. a. A partial split or break; a fissure. b. A slight, narrow space: The window was open a crack. 3. A sharp, resounding blow. 4. a. A mental or physical impairment; a defect. b. A breaking, harshly dissonant vocal tone or sound, as in hoarseness. 5. An attempt or try: gave him a crack at the job; took a crack at photography. 6. A witty or sarcastic remark. See note at joke . 7. A moment; an instant: at the crack of dawn. 8. Slang Chemically purified, very potent cocaine in pellet form that is smoked through a glass pipe and is considered highly and rapidly addictive. adj. 1. Excelling in skill or achievement; first-rate: a crack shot; a crack tennis player.

Phrasal Verbs: crack down 1. To act more forcefully to regulate, repress, or restrain: The police cracked down on speeding. crack up Informal 1. To praise highly: He was simply not the genius he was cracked up to be. 2. a. To damage or wreck (a vehicle or vessel): crack up a plane; crack up a boat. b. To wreck a vehicle in an accident: cracked up on the expressway. 3. To have a mental or physical breakdown. 4. To experience or cause to experience a great deal of amusement: really cracked up when I heard that joke.

Idioms: crack the whip 1. To behave in a domineering manner; demand hard work and efficiency from those under one's control. [Middle English craken from Old English cracian; See ger …- 2 in Indo-European Roots.]

drachm ( dr²m) n. 1. A dram. 2. A drachma.

fra·cas ( fr³"k…s, fr ²k"…s) n. Informal 1. A noisy, disorderly fight or quarrel; a brawl. See note at brawl . [French from Italian fracasso from fracassare to make an uproar]

grace ( gr³s) n. 1. Seemingly effortless beauty or charm of movement, form, or proportion. See note at elegance . 2. A characteristic or quality pleasing for its charm or refinement. 3. A sense of fitness or propriety. 4. a. A disposition to be generous or helpful; goodwill. b. Mercy; clemency. 5. A favor rendered by one who need not do so; indulgence. 6. A temporary immunity or exemption; a reprieve. 7. Graces Greek Mythology Roman Mythology Three sister goddesses, known in Greek mythology as Aglaia, Euphrosyne, and Thalia, who dispense charm and beauty. 8. Theology a. Divine love and protection bestowed freely on people. b. The state of being protected or sanctified by the favor of God. c. An excellence or a power granted by God. 9. A short prayer of blessing or thanksgiving said before or after a meal. 10. Grace Used with His, Her, or Your as a title and form of address for a duke, a duchess, or an archbishop. 11. Music An embellishment such as an appoggiatura or a trill. v. tr. graced grac·ing grac·es 1. To honor or favor: You grace our table with your presence. 2. To give beauty, elegance, or charm to. 3. Music To embellish with grace notes.

Idioms: in the bad graces of 1. Out of favor with. in the good graces of 1. In favor with. with bad grace 1. In a grudging manner. with good grace 1. In a willing manner. [Middle English from Old French from Latin gr³tia from gr³tus pleasing; See g w er…- 2 in Indo-European Roots.]

grace ( gr³s) n. 1. Seemingly effortless beauty or charm of movement, form, or proportion. See note at elegance . 2. A characteristic or quality pleasing for its charm or refinement. 3. A sense of fitness or propriety. 4. a. A disposition to be generous or helpful; goodwill. b. Mercy; clemency. 5. A favor rendered by one who need not do so; indulgence. 6. A temporary immunity or exemption; a reprieve. 7. Graces Greek Mythology Roman Mythology Three sister goddesses, known in Greek mythology as Aglaia, Euphrosyne, and Thalia, who dispense charm and beauty. 8. Theology a. Divine love and protection bestowed freely on people. b. The state of being protected or sanctified by the favor of God. c. An excellence or a power granted by God. 9. A short prayer of blessing or thanksgiving said before or after a meal. 10. Grace Used with His, Her, or Your as a title and form of address for a duke, a duchess, or an archbishop. 11. Music An embellishment such as an appoggiatura or a trill. v. tr. graced grac·ing grac·es 1. To honor or favor: You grace our table with your presence. 2. To give beauty, elegance, or charm to. 3. Music To embellish with grace notes.

Idioms: in the bad graces of 1. Out of favor with. in the good graces of 1. In favor with. with bad grace 1. In a grudging manner. with good grace 1. In a willing manner. [Middle English from Old French from Latin gr³tia from gr³tus pleasing; See g w er…- 2 in Indo-European Roots.]

or·ach also or·ache ( ôr"¹ch, ¼ r"-) n. 1. Any of various plants of the genus Atriplex, especially A. hortensis, having edible, spinachlike leaves. [Middle English orage arage from Old French arrache from Vulgar Latin * ³tripica from Latin ³triplex ³triplic-from Greek atraphaxus]

or·a·cle ( ôr"…-k…l, ¼ r"-) n. 1. a. A shrine consecrated to the worship and consultation of a prophetic deity, as that of Apollo at Delphi. b. A person, such as a priestess, through whom a deity is held to respond when consulted. c. The response given through such a medium, often in the form of an enigmatic statement or allegory. 2. a. A person considered to be a source of wise counsel or prophetic opinions. b. An authoritative or wise statement or prediction. 3. Theology A command or revelation from God. 4. In the Old Testament, the sanctuary of the Temple. [Middle English from Old French from Latin ½r³culum from ½r³re to speak]

trace 1 ( tr³s) n. 1. a. A visible mark, such as a footprint, made or left by the passage of a person, an animal, or a thing. b. Evidence or an indication of the former presence or existence of something; a vestige. 2. A barely perceivable indication; a touch: spoke with a trace of sarcasm. 3. a. An extremely small amount. b. A constituent, such as a chemical compound or element, present in quantities less than a standard limit. 4. A path or trail that has been beaten out by the passage of animals or people. 5. A way or route followed. 6. A line drawn by a recording instrument, such as a cardiograph. 7. Mathematics a. The point at which a line, or the curve in which a surface, intersects a coordinate plane. b. The sum of the elements of the principal diagonal of a matrix. 8. An engram. v. traced trac·ing trac·es v. tr. 1. To follow the course or trail of: trace a wounded deer; tracing missing persons. 2. To ascertain the successive stages in the development or progress of: tracing the life cycle of an insect; trace the history of a family. 3. To locate or discover by searching or researching evidence: trace the cause of a disease. 4. To draw (a line or figure); sketch; delineate. 5. To form (letters) with special concentration or care. 6. To copy by following lines seen through a sheet of transparent paper. 7. a. To imprint (a design) by pressure with an instrument on a superimposed pattern. b. To make a design or series of markings on (a surface) by such pressure on a pattern. 8. To record (a variable), as on a graph. v. intr. 1. To make one's way along a trail or course: traced through the files. 2. To have origins; be traceable: linguistic features that trace to West Africa. [Middle English track from Old French from tracier to make one's way from Vulgar Latin *tr ³cti³re from Latin tr³ctus a dragging, course, from past participle of trahere to draw] trace "a·bil"i·ty or trace "a·ble·ness n. trace "a·ble adj. trace "a·bly adv.

Synonyms: trace vestige track trail These nouns denote a visible sign or perceptible indication of the passage or former presence of something. Trace applies to both physical and immaterial evidence: I immediately recognized the charred traces of a fire. Despite his excellent English, he still retains the faint trace of a French accent. Vestige refers to a surviving remnant of what once existed or is past: " long lines of edifices, vestiges of whose ruins may still be found " (William Hickling Prescott); " vestiges of a very universal custom " (Henry Hallam). Track usually denotes a mark or succession of marks, as footprints, left by something that has passed: Archaeologists excavated fossilized dinosaur tracks from the riverbed. Trail can refer to the tracks of a person or an animal, especially one being hunted: " We came across the recent trails of but two of the animals we were after " (Theodore Roosevelt).

trac·er ( tr³"s…r) n. 1. a. One who is employed to locate missing goods or persons. b. An investigation or inquiry organized to trace missing goods or persons. 2. Any of several instruments used in making tracings or in imprinting designs by tracing. 3. A tracer bullet. 4. Chemistry An identifiable substance, such as a dye or a radioactive isotope, that is introduced into a biological or mechanical system and can be followed through the course of a process, providing information on the pattern of events in the process or on the redistribution of the parts or elements involved. In this sense, also called label .

track ( tr²k) n. 1. a. A mark or succession of marks left by something that has passed. See note at trace 1 . b. A path, route, or course indicated by such marks: an old wagon track through the mountains. 2. A path along which something moves; a course: following the track of an airplane on radar. 3. a. A course of action; a method of proceeding: on the right track for solving the puzzle. b. An intended or proper course: putting a stalled project back on track. 4. A succession of ideas; a train of thought. 5. Awareness of something occurring or passing: keeping track of the score; lost all track of time. 6. Sports a. A course laid out for running or racing. b. Athletic competition on such a course; track events. c. Track and field. 7. A rail or set of parallel rails upon which railroad cars or other vehicles run. 8. A metal groove or ridge that holds, guides, and reduces friction for a moving device or apparatus. 9. Any of several courses of study to which students are assigned according to ability, achievement, or needs: academic, vocational, and general tracks. 10. a. A distinct path, as along a length of film or magnetic tape, on which sound or other information is recorded. b. A distinct selection from a sound recording, such as a phonograph record or compact disk, usually containing an individual work or part of a larger work: the title track of an album. c. One of the separate sound recordings that are combined so as to be heard simultaneously, as in stereophonic sound reproduction: mixed the vocal track and instrumental track. v. tracked track·ing tracks v. tr. 1. To follow the tracks of; trail: tracking game through the forest. 2. To pursue successfully: " When, like a running grave, time tracks you down " Dylan Thomas 3. To move over or along; traverse. 4. To carry on the shoes and deposit: tracked mud on the rug. 5. To observe or monitor the course of (aircraft, for example), as by radar. 6. To observe the progress of; follow: tracking the company's performance daily. 7. To equip with a track. 8. To assign (a student) to a curricular track. v. intr. 1. To move along a track. 2. To follow a course; travel. 3. To keep a constant distance apart. Used of a pair of wheels. 4. To be in alignment.

Idioms: in (one's) tracks 1. Exactly where one is standing: stopped him right in his tracks. [Middle English trak from Old French trac perhaps of Germanic origin] track "a·ble adj. track "er n.

tract 1 ( tr²kt) n. 1. a. An expanse of land or water. b. A specified or limited area of land: developing a 30-acre tract. 2. Anatomy a. A system of organs and tissues that together perform a specialized function: the alimentary tract. b. A bundle of nerve fibers having a common origin, termination, and function. 3. Archaic A stretch or lapse of time. [Middle English period of time from Latin tr³ctus course, space, period of time, from past participle of trahere to draw]

tract 2 ( tr²kt) n. 1. A leaflet or pamphlet containing a declaration or an appeal, especially one put out by a religious or political group. [Middle English tracte treatise probably short for Latin tr³ct³tus,from past participle of tr³ct³reto discuss, frequentative of trahere to draw]

tract 3 ( tr²kt) n. 1. The verses from Scripture sung during Lent or on Ember days after the gradual in the Roman Catholic Mass. [Middle English tracte from Medieval Latin tr³ctus from Latin a drawing out (from its being an uninterrupted solo); See tract 1 ]

u·ra·cil ( y‹r"…-s¹l) n. 1. A pyrimidine base, C 4 H 4 N 2 O 2 , that is an essential constituent of RNA. [ ur(ea) ac(etic) -il substance relating to]

wrack 1 also rack ( r²k) n. 1. Destruction or ruin. 2. A remnant or vestige of something destroyed. [Middle English from Old English wræc punishment( influenced by Middle Dutch wrak shipwreck) ]

wrack 2 also rack ( r²k) n. 1. a. Wreckage, especially of a ship cast ashore. b. Chiefly British Violent destruction of a building or vehicle. 2. a. Dried seaweed. b. Marine vegetation, especially kelp. v. wracked also racked wrack·ing rack·ing wracks racks v. tr. 1. To cause the ruin of; wreck. v. intr. 1. To be wrecked. [Middle English wrak from Middle Dutch]