have a laugh

enough to make a cat laugh

Very outlandish or outrageous.

have the last laugh

To be vindicated; to triumph despite predicted failure; to find success after defeat or setback.

laugh a minute

A funny thing or person.

laugh all the way to the bank

To make a large income easily, especially at the expense of others or by doing something that lacks significant merit or effort.

laugh in one's sleeve

to laugh in secret or to oneself, usually gloatingly

laugh one's head off

To laugh uproariously.

laugh out of court

To dismiss as silly something presented with genuine conviction or treated seriously.

laugh up one's sleeve

Alternative form of laugh in one's sleeve.