No ground of enmity between us known Why he should mean me ill or seek
to harm.
Milton.
Turn the discourse; I have a reason why I would not have you speak so
tenderly.
Dryden.
3. The reason or cause for which; that on account of which; on what
account; as, I know not why he left town so suddenly; — used as a
compound relative.
Why is sometimes used as an interjection or an expletive in expression
of surprise or content at a turn of affairs; used also in calling.
"Why, Jessica!" Shak.
If her chill heart I can not move, Why, I'll enjoy the very love.
Cowley.
Sometimes, also, it is used as a noun.
The how and the why and the where.
Goldsmith.