(of a gay or bisexual man (or, rarely, of a lesbian), potentially offensive) Having the appearance, mannerisms, etc., of a stereotypical heterosexual of the same gender rather than those stereotypically associated with gay men or lesbians.

present participle of act out

(pharmacology) Having a pharmaceutical effect principally in the short term.

(pharmacology) Having a pharmaceutical effect principally in the long term.

present participle of act up

(genetics) Describing transcription factors that regulate the expression of genes on the same chromosome.

(genetics) Describing transcription factors that regulate the expression of genes on a different chromosome.

(acting) An acting technique in which the actor fully immerses themselves into the character they are playing.

(engineering) Having simplicity of action; especially acting or exerting force during strokes in one direction only; said of a reciprocating engine, pump, etc.

Acting of or by itself.