n., v., & adj.
--n.
1. a a sudden sharp or explosive noise (the crack of a whip; a rifle crack). b (in a voice) a sudden harshness or change in pitch.
2 a sharp blow (a crack on the head).
3 a a narrow opening formed by a break (entered through a crack in the wall). b a partial fracture, with the parts still joined (the teacup has a crack in it). c a chink (looked through the crack formed by the door; a crack of light).
4 colloq. a mischievous or malicious remark or aside (a nasty crack about my age).
5 colloq. an attempt (I'll have a crack at it).
6 the exact moment (at the crack of noon; the crack of dawn).
7 colloq. a first-rate player, horse, etc.
8 dial. colloq. conversation; good company; fun (only went there for the crack).
9 sl. a potent hard crystalline form of cocaine broken into small pieces and inhaled or smoked for its stimulating effect.
--v.
1. tr. & intr. break without a complete separation of the parts (cracked the window; the cup cracked on hitting the floor).
2 intr. & tr. make or cause to make a sudden sharp or explosive sound.
3 intr. & tr. break or cause to break with a sudden sharp sound.
4 intr. & tr. give way or cause to give way (under torture etc.); yield.
5 intr. (of the voice, esp. of an adolescent boy or a person under strain) become dissonant; break.
6 tr. colloq. find a solution to (a problem, code, etc.).
7 tr. say (a joke etc.) in a jocular way.
8 tr. colloq. hit sharply or hard (cracked her head on the ceiling).
9 tr. Chem. decompose (heavy oils) by heat and pressure with or without a catalyst to produce lighter hydrocarbons (such as petrol).
10 tr. break (wheat) into coarse pieces.
--attrib.adj. colloq. excellent; first-rate (a crack regiment; a crack shot).
Phrases and idioms:
crack a bottle open a bottle, esp. of wine, and drink it. crack-brained crazy. crack a crib sl. break into a house. crack-down colloq. severe measures (esp. against law-breakers etc.). crack down on colloq. take severe measures against. crack-jaw colloq.
--adj. (of a word) difficult to pronounce.
--n. such a word. crack of doom a thunder-peal announcing the Day of Judgement. crack up colloq.
1. collapse under strain.
2 praise. crack-up n.
colloq.
1. a mental breakdown.
2 a car crash. crack-willow a species of willow, Salix fragilis, with brittle branches. fair crack of the whip colloq. a fair chance to participate etc. get cracking colloq. begin promptly and vigorously. have a crack at colloq. attempt.
Etymology: OE cracian resound