to break or to make something break, either so that it gets lines on its surface, or so that it breaks into pieces:
break[intransitive and transitive]
Don't put boiling water in the glass or it will crack.
Concrete is liable to crack in very cold weather.
He picked up a piece of rock and cracked it in half.
She fell and cracked a bone in her leg.
He cracked a couple of eggs into a pan.
to make a quick loud sound like the sound of something breaking, or to make something do this:
sound[intransitive and transitive]C
Thunder cracked overhead.
He cracked his whip and galloped off.
Dennis rubbed his hands together and cracked his knuckles.
to hit someone or something hard
crack something on something
I slipped and cracked my head on the door.
She cracked him over the head with a hammer.
to be unable to continue doing something because there is too much pressure and you do not have the mental strength to continue
not be able to continue[intransitive]MI
Some young executives crack under the pressure of having to meet tough sales targets every month.
He cracked under interrogation and confessed.
if your voice cracks, it starts to sound different because you are feeling strong emotions:
His voice cracked slightly as he tried to explain.
to find the answer to a problem or manage to understand something that is difficult to understand [= solve]:
I think we've cracked the problem of the computer crashing all the time.
It took them nearly two months to crack the code.
This new evidence could help detectives to crack the case.
to stop a person from being successful:
stop somebody[transitive] informal
Political enemies have tried to crack me.
to open a safe illegally in order to steal the things inside it
open a safe[transitive]SCC
to illegally copy computer software or change free software which may lack certain features of the full version, so that the free software works in the same way as the full version:
You can find out how to crack any kind of software on the web.
10 British English informal
to manage to do something successfully:
I think we've cracked it!
He seems to have got it cracked.
to tell a joke:
He kept cracking jokes about my appearance.
12 British English informal
to open a bottle of alcohol for drinking:
We cracked open a few bottles.
to start doing something or going somewhere quickly:
I think we need to get cracking if we're going to catch this train.
to make people work very hard
used to say that something is not as good as people say it is:
I thought the film was OK, but it's not all it's cracked up to be.
crack downphrasal verb
crack into somethingphrasal verb
to secretly enter someone else's computer system, especially in order to damage the system or steal the information stored on it [↪ hack]:
A teenager was accused of cracking into the company's network.
crack onphrasal verb
crack on with
I need to crack on with my project work this weekend.
crack upphrasal verb
to laugh a lot at something, or to make someone laugh a lot:
Everyone in the class just cracked up.
She's so funny. She cracks me up.
to become unable to think or behave sensibly because you have too many problems or too much work:
I was beginning to think I was cracking up!