(slang) Used other than figuratively or idiomatically: see that's, what's up. / (slang) Used to express acquiescence or concurrence; true; indeed.

(mildly vulgar, slang) An intensive form of what. / (mildly vulgar, slang) Indicating acceptance, indulgence, or insouciance: Why not? Who cares?

(euphemistic) what the hell

(colloquial, rhetorical question, impolite) A reply to an unimportant or irrelevant statement, indicating indifference on the part of the speaker.

plural of what for

(slang) What’s going on with you? (as a greeting)

(slang) What’s going on with you?

(colloquial, often with a following present participle or infinitive expression) Used to indicate that a specified or implied action cannot succeed or offers no advantage if successful

Euphemistic form of what the fuck.

(slang) what's happening?; what's up? (a greeting)