(interrogative) Which thing, event, circumstance, etc.: used in asking for the specification of an identity, quantity, quality, etc. / (fused relative) That which; those that; the thing(s) that.

(interrogative) In what way; to what extent.

(idiomatic) Owing to; because of; as a result of.

(literally, sometimes philosophical) This thing has its own distinct nature; this thing is itself.

For what purpose. / (colloquial) For what reason; why.

(idiomatic, colloquial, usually with "give someone") An unspecified punishment or rebuke

(idiomatic) So what? Who cares? Expresses disinterest, disregard or lack of concern.

(informal) A speculation as to what might have happened if something else had happened earlier.

(informal) To speculate about the consequences of something that could have happened.

Used to ask the listener what they want.