/hwuy, wuy/ , adv., conj., n., pl. whys , interj.
adv.
1. for what? for what reason, cause, or purpose?: Why did you behave so badly?
conj.
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.
n.
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.
interj.
7. (used as an expression of surprise, hesitation, etc., or sometimes a mere expletive): Why, it's all gone!
[ bef. 900; ME; OE hwi, hwy, instr. case of hwaet WHAT; c. ON hvi ]
Usage . See reason .