(defensively) Why are you asking? Why do you want to know?. / Mind your own business; it's none of your business.

(US) A shop selling miscellanea.

(African-American Vernacular) What's up? What's going on?

(informal) An informal greeting.

(idiomatic) Used to add emphasis to “what” when beginning a question.

(idiomatic) The latest developments in a particular situation or a person's life.

(informal) An informal greeting asking the other person what has recently happened in their life. A typical response might be "Not much; you?". The greeting is not always literal and may just be used to say hello.

Used to express regret or disappointment about an unfortunate event or piece of information.

plural of what-if

present participle of what-if