1 A2 idiomatic informal
To burst out laughing uncontrollably.
"She cracked up when he tripped over the garden hose."
inseparable
crack up
B1 informal separable transitive/intransitive
To burst out laughing, to cause someone to laugh, or to suffer a mental or emotional collapse.
In plain English
To start laughing really hard, or to stop working properly in your mind.
What does "crack up" mean?
4 meanings, ordered from most common to least. Color-coded by CEFR level.
2 B1 idiomatic informal
To cause someone else to laugh uncontrollably.
"His impression of the boss always cracks the whole team up."
separable
3 B2 idiomatic informal
To suffer a mental or emotional breakdown under stress or pressure.
"After months of overwork and no sleep, he finally cracked up."
inseparable
4 B2 idiomatic informal
Used in the fixed expression 'not all it's cracked up to be', meaning not as good as people say.
"Fame isn't all it's cracked up to be — the loss of privacy is exhausting."
“
It's not all it's cracked up to be.
— Common idiomatic expression widely attributed in popular press and interviews, e.g. used by various celebrities discussing fame.
inseparable
Literal vs figurative
Words literally mean
To split or fracture upward — as if pressure from within causes something to break apart.
Actually means
To start laughing really hard, or to stop working properly in your mind.
Usage tip
The 'laughing' sense is very common in everyday speech. The 'mental breakdown' sense is more serious. The phrase 'not all it's cracked up to be' is a fixed idiomatic expression meaning something is not as good as people claim.
Words that pair with "crack up"
Natural word combinations native speakers use most often.
audience class crowd friends everyone tears
How to conjugate "crack up"
The five tense forms you'll use most often.
Base
crack up
I/you/we/they
3rd person
cracks up
he/she/it
Past simple
cracked up
yesterday
Past participle
cracked up
have + pp
-ing form
cracking up
continuous
Hear "crack up" in the wild
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Other ways to say "crack up"
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Keep exploring
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