Alternative form of one-upmanship

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.

(music) A style of drumming, prevalent in reggae and attributed to Winston Grennan, in which the snare and bass play on the same beat.

(golf) A hole that is completed by sinking the ball in a single shot or attempt, with one hit. / (by extension, idiomatic) Any rare, wonderful, or remarkable accomplishment.

(idiomatic) Alone; by oneself; without the companionship or assistance of others.

(cricket) The act of a batsman, running between the wickets, failing to ground himself or his bat behind the popping crease before turning for another run; the umpire's signal indicating this (the run does not count).

A short joke, especially one of a single sentence. / A short remark intended as a sound bite. / (computing) A command or small program consisting of a single line of input.

(idiomatic) Drunk; in the act of consuming alcohol liberally.

(US, colloquial) murder in the first degree.