(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.

(rhetorical question, colloquial, childish) Assertion that an insult made by the party to whom the phrase is directed is actually true of that party, and not of the person using the phrase. Usually considered to be a playground taunt.

History (or progress) moves ahead, no matter the criticism it may attract.

plural of butadiynyl

(academics) A status of a doctoral student who has completed all PhD degree requirements except the doctoral dissertation.

(organic chemistry, especially in combination) Any substituent derived from butadiene