early 15c., "impairment, infringement," from Middle French énervation, from Late Latin enervationem (nominative enervatio), noun of action from past participle stem of Latin enervare "weaken," literally "cut the sinews of," from ex- "out" (see ex-) + nervus "sinew" (see nerve (n.)). Figurative sense is from 1550s.[enervation etymology, enervation origin, 英语词源]