to express mirth, pleasure, derision, or nervousness with an audible, vocal expulsion of air from the lungs that can range from a loud burst of sound to a series of quiet chuckles and is usually accompanied by characteristic facial and bodily movements.

to experience the emotion so expressed

He laughed inwardly at the scene.

to produce a sound resembling human laughter

A coyote laughed in the dark.

to drive, put, bring, etc., by or with laughter (often fol. by out, away, down, etc.)

They laughed him out of town. We laughed away our troubles.

to utter with laughter

He laughed his consent.

the act or sound of laughing; laughter.

an expression of mirth, derision, etc., by laughing.

Informal . something that provokes laughter, amusement, or ridicule

After all the advance publicity, the prizefight turned out to be a laugh.

laughs, Informal . fun; amusement. ?

laugh at,

to make fun of; deride; ridicule

They were laughing at him, not along with him.

to be scornful of; reject

They stopped laughing at the unusual theory when it was found to be predictive.

to find sympathetic amusement in; regard with humor

We can learn to laugh a little at even our most serious foibles.

laugh off, to dismiss as ridiculous, trivial, or hollow

He had received threats but laughed them off as the work of a crank.

have the last laugh

to prove ultimately successful after a seeming defeat or loss

She smiled slyly, because she knew she would yet have the last laugh on them.

laugh out of court

to dismiss or depreciate by means of ridicule; totally scorn

His violent protests were laughed out of court by the others.

laugh out of the other side of one's mouth. to undergo a chastening reversal, as of glee or satisfaction that is premature; be ultimately chagrined, punished

etc.; cry

She's proud of her promotion, but she'll laugh out of the other side of her mouth when the work piles up. Also, laugh on the wrong side of one's mouth or face.

laugh up one's sleeve. sleeve ( def. 6 ) .