Etymology: Middle English crakken, from Old English cracian; akin to Old High German chrahhōn to resound
Date: before 12th century
1. to make a very sharp explosive sound <the whip cracks through the air> 2. to break, split, or snap apart 3. fail: as a. to lose control or effectiveness under pressure — often used with up b. to fail in tone <his voice cracked> 4. to go or travel at good speed — usually used with on <the steamboat cracked on> transitive verb 1. a. to break so that fissures appear on the surface <crack a mirror> b. to break with a sudden sharp sound <crack nuts> 2. to tell especially suddenly or strikingly <crack a joke> 3. to strike with a sharp noise ; rap <then cracks him over the head> <cracked a two-run homer in the fifth — New York Times> 4. a. (1) to open (as a bottle) for drinking (2) to open (a book) for studying b. to puzzle out and expose, solve, or reveal the mystery of <crack a code> c. to break into <crack a safe> d. to open slightly <crack the throttle> e. to break through (as a barrier) so as to gain acceptance or recognition f. to show or begin showing (a smile) especially reluctantly or uncharacteristically 5. a. to impair seriously or irreparably ; wreck <crack an opponent's courage> b. to destroy the tone of (a voice) c. disorder, craze d. to interrupt sharply or abruptly <the criticism cracked our complacency> 6. to cause to make a sharp noise <cracks his knuckles> 7. a. (1) to subject (hydrocarbons) to cracking (2) to produce by cracking <cracked gasoline> b. to break up (chemical compounds) into simpler compounds by means of heat II. noun Date: 14th century 1. a. a loud roll or peal <a crack of thunder> b. a sudden sharp noise <the crack of rifle fire> 2. a sharp witty remark ; quip 3. a. a narrow break ; fissure <a crack in the ice> b. a narrow opening <leave the door open a crack> <cracks between floorboards> — used figuratively in phrases like fall through the cracks to describe one that has been improperly or inadvertently ignored or left out <a player who fell through the cracks in the college draft> <children slipping through the cracks of available youth services> 4. a. a weakness or flaw caused by decay, age, or deficiency ; unsoundness b. a broken tone of the voice c. crackpot 5. moment, instant <the crack of dawn> 6. housebreaking, burglary 7. a sharp resounding blow <gave him a crack on the head> 8. an attempt or opportunity to do something <her first crack at writing a novel> <got first crack at the job opening> 9. a potent form of cocaine that is obtained by treating the hydrochloride of cocaine with sodium bicarbonate to create small chips used illicitly for smoking — called also crack cocaine III. adjective Date: 1793 of superior excellence or ability <a crack marksman>
New Collegiate Dictionary. 2001.