v. cracked, crack·ing, cracks v.intr. 1. a. To break without complete separation of parts: The mirror cracked. b. To break or snap apart: The branch cracked off and fell. 2. To make a sharp snapping sound: His knees cracked as he sat down. 3. a. To break down; fail: The defendant's composure finally began to crack. b. To have a mental or physical breakdown: cracked under the pressure. 4. To change sharply in pitch or timbre, as from hoarseness or emotion. Used of the voice. 5. To move or go rapidly: was cracking along at 70 miles an hour. 6. Chemistry To break into simpler molecules, often by means of heat or a catalyst. v.tr. 1. a. To cause to break without complete separation of parts: The pebble cracked the car's windshield. See Synonyms at break. b. To cause to break with a sharp snapping sound: crack nuts. c. To crush (corn or wheat, for example) into small pieces. 2. a. To strike, especially with a sharp sound: cracked the intruder over the head with a lamp. b. To cause to come into forceful contact with something, especially with a sharp sound: fell and cracked his head against the floor. 3. To open to a slight extent: crack a window to let in some air. 4. 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 acknowledgment: finally cracked the "men-only" rule at the club. 5. To discover the solution to, especially after considerable effort: crack a code. 6. To cause (the voice) to crack. 7. Informal To tell (a joke), especially on impulse or in an effective manner. 8. To cause to have a mental or physical breakdown. 9. To impair or destroy: Their rude remarks cracked his equanimity. 10. To reduce (petroleum) to simpler compounds by cracking. n. 1. a. A partial split or break; a fissure: cracks in the basement wall. b. A slight narrow space: The window was open a crack. c. Informal The fissure between the buttocks. 2. A defect or flaw: cracks in the argument; a crack in his composure. 3. A sharp snapping sound, such as the report of a firearm. 4. A sharp resounding blow: gave him a crack on the head. 5. A breaking, harshly dissonant vocal tone or sound, as in hoarseness. 6. An attempt or try: gave him a crack at the job; took a crack at photography. 7. A witty or sarcastic remark. See Synonyms at joke. 8. A moment; an instant: at the crack of dawn. 9. Irish Fun had when socializing; social amusement. 10. Slang Crack cocaine. adj. Phrasal Verbs: Excelling in skill or achievement; first-rate: a crack shot; a crack tennis player. crack down To act more forcefully to regulate, repress, or restrain: The police cracked down on speeding. crack up Informal Idiom: 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: crack up from overwork. 4. To experience or cause to experience a great deal of amusement: really cracked up when I heard that joke. crack the whip 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 gerə-2 in the Appendix of Indo-European roots.] |
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