Very amusing or entertaining.

colloquial. Highly entertaining or amusing; preposterous, outrageous (esp. in a bit rich). Frequently in that's rich!: expressing ironic amusement or…

In hyperbolic use: Able to kill. ‘Excruciatingly’ funny; that makes one ‘die’ with laughing. colloquial.

To a degree that causes hysterical laughter. Chiefly in hysterically funny: extremely funny, hilarious.

In weakened use: extremely funny; highly amusing or absurd.

Likely to cause one to laugh out loud; hilarious.