but

/ˈbət/

Middle English, from Old English būtan, preposition & conjunction, outside, without, except, except that; akin to Old High German būzan without, except; akin to Old English be by, ūt out

conjunction

  1. except for the fact

  2. that —used after a negative

  3. without the concomitant that

would have protested but that he was afraid

preposition

  1. with the exception of : barring

  2. other than

  3. without, lacking

no one there but me

this letter is nothing but an insult

adverb

  1. only, merely

  2. outside

  3. to the contrary

he is but a child