- energy (n.)
- 1590s, "force of expression," from Middle French énergie (16c.), from Late Latin energia, from Greek energeia "activity, operation," from energos "active, working," from en "at" (see en- (2)) + ergon "work, that which is wrought; business; action" (see urge (v.)).
Used by Aristotle with a sense of "force of expression;" broader meaning of "power" is first recorded in English 1660s. Scientific use is from 1807. Energy crisis first attested 1970.