Contraction of but has. / Contraction of but is.

(organic chemistry) The diketone CH₃-CO-CO-CH₃ that is used in organic synthesis

(idiomatic) To a high degree; very thoroughly; in a most definite manner.

only

(pharmacology) The United States Adopted Name of secbutabarbital.

(pharmacology) A local anesthetic.

(Northern England, idiomatic) Used at the end of a sentence to add emphasis.

Alternative form of sticks and stones may break my bones, but words will never hurt me.

(ethnic slur, offensive) Black people, in the view of racists, behave badly regardless of their whereabouts or socialization.

(idiomatic) Temporarily incapacitated but not permanently defeated.