on the contrary; yet

My brother went, but I did not.

except; save

She was so overcome with grief she could do nothing but weep.

unless; if not; except that (fol. by a clause, often with that expressed)

Nothing would do but that I should come in.

without the circumstance that

It never rains but it pours.

otherwise than

There is no hope but by prayer.

that (used esp. after doubt, deny, etc., with a negative)

I don't doubt but he will do it.

who not; that not

No leaders worthy of the name ever existed but they were optimists.

(used as an intensifier to introduce an exclamatory expression)

But she's beautiful!

Informal . than

It no sooner started raining but it stopped.

with the exception of; except; save

No one replied but me.

only; just

There is but one God.

buts, reservations or objections

You'll do as you're told, no buts about it.

but for

except for; were it not for

But for the excessive humidity, it might have been a pleasant day.

but what. what ( def. 24 ) .

conjuction, preposition

however , on the other hand , nevertheless , still , yet , though , although , except , disregarding , without , not including , aside from , passing over , barring , omitting

adverb

alone , entirely , exclusively , only