Why? An update to the dictionary...

Definition from Dictionary.com:

why - adverb, conjunction, noun, plural whys, interjection

–adverb
1.for what? for what reason, cause, or purpose?: Why did you behave so badly?

–conjunction
2.for what cause or reason: I don't know why he is leaving.
3.for which; on account of which (usually after reason to introduce a relative clause): the reason why he refused to go.
4.the reason for which: That is why he returned.

–noun
5.a question concerning the cause or reason for which something is done, achieved, etc.: a child's unending hows and whys.
6.the cause or reason: the whys and wherefores of a troublesome situation.

–interjection
7.(used as an expression of surprise, hesitation, etc., or sometimes a mere expletive): Why, it's all gone!

Dictionary.com Unabridged (v 1.1)Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.

Needs to be added:
8. Kyle's new favorite question.