Meaning

noun the highest level or degree attainable; the highest stage of development

noun the highest point (of something)

originFrom acme (“highest, best”). As a threading, from the original 1894 manufacturer, the Acme Screw Machine Company of Hartford, Connecticut. In its use as a generic company for comedic effect or to avoid trademark issues, most popularized by the Warner Bros.' Looney Tunes cartoons but already very commonly used by 20th century American companies as a way to lead the professional listings in yellow…

Etymology from Wiktionary, CC BY-SA 3.0