Definition of crack verb from the Oxford Advanced Learner's Dictionary

Oxford3000

crack

verb
kræk
 
; kræk
 
 
 

break

1 [intransitive, transitive] to break without dividing into separate parts; to break something in this wayThe ice cracked as I stepped onto it.crack something He has cracked a bone in his arm.Her lips were dry and cracked.2 [intransitive, transitive] to break open or into pieces; to break something in this way+ adverb/preposition A chunk of the cliff had cracked off in a storm. (figurative) His face cracked into a smile.crack something to crack a nutcrack something + adverb/preposition She cracked an egg into the pan.
 

hit

3 [transitive] crack something/somebody (on/against something) to hit something/somebody with a short hard blowI cracked my head on the low ceiling.He cracked me on the head with a ruler.
 

make sound

4 [intransitive, transitive] to make a sharp sound; to make something do thisA shot cracked across the ridge. [no passive]crack something He cracked his whip and galloped away.
 

of voice

5 [intransitive] if your voice cracks, it changes in depth, volume, etc. suddenly and in a way that you cannot controlIn a voice cracking with emotion, he told us of his son's death.
 

under pressure

6 [intransitive] to no longer be able to function normally because of pressureThings are terrible at work and people are cracking under the strain.They questioned him for days before he cracked.The old institutions are cracking.
 

find solution

7 [transitive] crack something to find the solution to a problem, etc; to find the way to do something difficultto crack the enemy's code (informal) After a year in this job I think I've got it cracked!
 

stop somebody/something

8 [transitive] crack something to find a way of stopping or defeating a criminal or an enemyPolice have cracked a major drugs ring.
 

open bottle

9 [transitive] crack (open) a bottle (informal) to open a bottle, especially of wine, and drink it
 

a joke

10 [transitive] crack a joke (informal) to tell a joke
Idioms

get cracking

(informal) to begin immediately and work quickly
Synonym
get going
There's a lot to be done, so let's get cracking.

not all, everything, etc. somebody's cracked up to be

(informal) not as good as people sayHe's not nearly such a good writer as he's cracked up to be.

crack the whip

to use your authority or power to make somebody work very hard, usually by treating them in a strict way
more at a hard/tough nut (to crack) at nut n., use a sledgehammer to crack a nut at sledgehammer
Phrasal verbs

crack down (on somebody/something)

to try harder to prevent an illegal activity and deal more severely with those who are caught doing itPolice are cracking down on drug dealers. related noun crackdown

crack on (with something)

(British English, informal) to work hard at something so that you finish it quickly; to pass or continue quicklyIf we crack on with the painting we should finish it today.Time was cracking on and we were nowhere near finished.

crack up

(informal)1 to become ill, either physically or mentally, because of pressureYou'll crack up if you carry on working like this.2 to start laughing a lotHe walked in and everyone just cracked up.

crack somebody up

(informal) to make somebody laugh a lotGill's so funny, she just cracks me up.