(interrogative) Which, especially which of an open-ended set of possibilities. / (relative) Which; the ... that. / (relative) Any ... that; all ... that; whatever.

(interrogative) In what way; to what extent.

(idiomatic) Or something else; allows for the existence of an unexpressed alternative to what was said.

Used to introduce a suggestion or proposal for a future event. / Used to introduce a speculation about a future event.

What is. / What has. / What does.

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

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

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

plural of what; used as a stand-in to collectively pluralize arbitrary instances of things. Often used along with whys, hows, etc.

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