Definitions from Wiktionary (crack up)

▸ verb:  To laugh.
▸ verb:  (idiomatic, intransitive) To laugh heartily.
▸ verb:  (idiomatic, transitive) To cause to laugh heartily.
▸ verb:  (slang, intransitive) To tease (someone) or tell jokes at the expense of (someone).
▸ verb:  To break.
▸ verb:  (idiomatic, intransitive, dated in US) To become insane; to suffer a mental breakdown.
▸ verb:  (idiomatic) To break down or fall apart; to stop functioning; to shatter.
▸ verb:  (idiomatic, transitive) To separate a group.
▸ verb:  (US) To crash an aircraft or automobile.
▸ verb:  (transitive) To remove the shell from nuts.
▸ verb:  (transitive) To crack (petroleum). (to break down (a complex molecule), especially with the application of heat: to pyrolyse)
▸ verb:  To affect the image of something.
▸ verb:  (slang, transitive) To praise or applaud (something); to promote a positive view of (something).
▸ verb:  (dated, transitive) To insult, demean or harm the image of (something).
▸ verb:  (transitive, informal, usually passive, usually negative) To cry up; to extol.
▸ verb:  (slang, intransitive) To smoke crack cocaine.
▸ adjective:  (New Zealand, colloquial) Funny; hilarious

---

▸ Words similar to crack up
▸ Usage examples for crack up

▸ Idioms related to crack up
▸ Wikipedia articles (New!)
▸ Popular nouns described by crack up
▸ Words that often appear near crack up
▸ Rhymes of crack up

▸ Invented words related to crack up