Preposition

1. Outside of, without.

   Away but the hoose and tell me whae's there.

Adverb

1. Merely, only.

   Since that day, my mood has changed but a little.

Conjunction

1. Except (for), excluding.

   I like everything but that. I have no choice but to leave.

2. On the contrary, but rather (introducing a word or clause that contrasts with or contradicts the preceding clause or sentence without the not).

   I am not rich but poor.

3. However, although, nevertheless (implies that the following clause is contrary to prior belief or contrasts with or contradicts the preceding clause or sentence).

   She is very old but still attractive. You told me I could do that but she said that I could not.

Usage notes

• Beginning a sentence with a coordinating conjunction such as but is considered incorrect by classical grammarians arguing that a coordinating conjunction at the start of a sentence has nothing to connect but use of the word in this way is very common. It is, however, best to avoid beginning a sentence with but in formal writing. Combining sentences or using however, nevertheless, still, or though is appropriate for the formal style.
  • But this tool has its uses.
  • This tool has its uses, however.
  • Nevertheless, this tool has its uses.
  • Still, this tool has its uses.
  • This tool still has its uses.
  • This tool has its uses, though.

• • I was very tired, but I decided to continue.
  • It was a lovely day, but rain looked likely.

Synonyms

• (1): bar, unless, except, excepting, excluding, with the exception of, without
• (2):
• (3): however, yet, although

Noun

1. An instance or example of using the word "but"

   It has to be done – no ifs or buts.

2. The outer room of a small two-room cottage.