Occurring once, independent of any pattern; one-time. / Singular; unique; special; remarkable.

(idiomatic) Something that is done, created, etc. only once, and often quickly, simply, or improvisationally. / Something unique and remarkable.

plural of one-off

(idiomatic, slang, vulgar) To defecate.

(slang) An act of masturbation.

(baseball, dated, slang, 1800s) To throw a curve ball.

(slang) To masturbate.

(slang) To fart; to break wind.

(UK, slang) Of a man: to masturbate to orgasm.

simple past tense of break one off