crack up

crack  (krk)

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 Synonyms at break.

b. To crush (corn or wheat, for example) into small pieces.

4. To open to a slight extent: cracked the window to let in some air.

5. To strike with a sudden sharp sound.

6. 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.

7. To discover the solution to, especially after considerable effort: crack a code.

8. To cause (the voice) to crack.

9. Informal To tell (a joke), especially on impulse or in an effective manner.

10. To cause to have a mental or physical breakdown.

11. To impair or destroy: Their rude remarks cracked his equanimity.

12. 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 Synonyms at joke.

7. A moment; an instant: at the crack of dawn.

8. Irish Fun; amusement.

9. Slang Crack cocaine.

adj.

Excelling in skill or achievement; first-rate: a crack shot; a crack tennis player.

Phrasal Verbs:

crack down

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: crack up from overwork.

4. To experience or cause to experience a great deal of amusement: really cracked up when I heard that joke.

Idiom:

crack the whip

To behave in a domineering manner; demand hard work and efficiency from those under one's control.

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[Middle English craken, from Old English cracian; see ger-² in Indo-European roots.]

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crack up

Verb

1. Informal to have a physical or mental breakdown

2. to begin to break into pieces: there are worrying reports of buildings cracking up as the earth dries out and foundations move

3. not all it is cracked up to be Informal not as good as people have claimed it to be

Noun

crackup

Informal a physical or mental breakdown

Thesaurus

Verb	1.	crack up - suffer a nervous breakdown crock up, collapse, break up, crack suffer, sustain, have, get - undergo (as of injuries and illnesses); "She suffered a fracture in the accident"; "He had an insulin shock after eating three candy bars"; "She got a bruise on her leg"; "He got his arm broken in the scuffle"
	2.	crack up - rhapsodize about exalt, extol, glorify, laud, proclaim - praise, glorify, or honor; "extol the virtues of one's children"; "glorify one's spouse's cooking"
	3.	crack up - laugh unrestrainedly break up express joy, express mirth, laugh - produce laughter