Huh?

[Tina]

The most common expression used after you have just asked a girl out.

[Becky]

Used as a cover-up when a person gives an awkward answer to a question.

[Rihanna]

A word that is always in anime.
Also, it is another word for what?, etc.

[Couch Potatoe]

The word used right after a question from someone who is persistent for an immediate answer. This person will often ask random questions just to start conversation without giving you a chance to reply before they ask another question.