(proscribed) Obstinate.

A programming language version of Ada for CLI, spelled A#.

(medicine) The introduction of a tube into an organ to keep it open, as into the larynx in cases of croup.

(intransitive, of the heart) To stop beating. / (intransitive, by extension) To die. / (transitive, slang) To kill. / To stay at the same level, without development; or, to fall.