However, although, nevertheless, on the other hand (introducing a clause contrary to prior belief or in contrast with the preceding clause or sentence).

Apart from, except (for), excluding. / (obsolete outside Scotland) Outside of.

An instance or example of using the word "but". / (Scotland) The outer room of a small two-room cottage. / A limit; a boundary.

(archaic) Use the word "but".

(chiefly literary or poetic) Merely, only, just, no more than / (Australia, Tyneside, conjunctive) Though, however.

(organic chemistry) Denotes the presence of four carbon atoms in the parent chain when forming names of organic compounds.

(obsolete) Unless.

plural of butadiene

A block copolymer consisting of two polystyrene chains, one each side of a polybutadiene sequence; they have both thermoset and thermoplastic properties.

Used to cut off objections or qualifications.