break1 [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.
hit3 [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 sound4 [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 voice5 [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 pressure6 [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 solution7 [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/something8 [transitive] crack something to find a way of stopping or defeating a criminal or an enemyPolice have cracked a major drugs ring.
open bottle9 [transitive] crack (open) a bottle (informal) to open a bottle, especially of wine, and drink it
a joke10 [transitive] crack a joke (informal) to tell a joke
get cracking(informal) to begin immediately and work quickly
Synonymget goingThere'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.
more at a hard/tough nut (to crack) at nut n., use a sledgehammer to crack a nut at sledgehammer
crack the whip
to use your authority or power to make somebody work very hard, usually by treating them in a strict way