Emily Dickinson Lexicon

AC'ME, n. [ac'my; Gr. αλμη.]

The top or highest point. It is used to denote the maturity or perfection of an animal. Among physicians, the crisis of a disease, or its utmost violence. Old medical writers divided the progress of a disease into four periods; the arche, or beginning, the anabasis, or increase, the acme, or utmost violence, and the paracme, or decline. But acme can hardly be considered as a legitimate English word.