word-forming element meaning "near, at, in, on, within," from Greek en "in," cognate with Latin in (from PIE root *en "in"), and thus with en- (1). Typically assimilated to em- before -p-, -b-, -m-, -l-, and -r-.

Proto-Indo-European root meaning "to do."

It forms all or part of: allergic; allergy; argon; boulevard; bulwark; cholinergic; demiurge; dramaturge; energy; erg (n.1) "unit of energy;" ergative; ergonomics; ergophobia; George; georgic; handiwork; irk; lethargic; lethargy; liturgy; metallurgy; organ; organelle; organic; organism; organize; orgy; surgeon; surgery; synergism; synergy; thaumaturge; work; wright; wrought; zymurgy.

It is the hypothetical source of/evidence for its existence is provided by: Greek ergon "work," orgia "religious performances;" Armenian gorc "work;" Avestan vareza "work, activity;" Gothic waurkjan, Old English wyrcan "to work," Old English weorc "deed, action, something done;" Old Norse yrka "work, take effect."

late 14c., "power, efficacy," from Medieval Latin actualitatem (nominative actualitas), from Late Latin actualis "pertaining to action," from Latin actus "a doing" (from PIE root *ag- "to drive, draw out or forth, move"). A Latin loan-translation of Greek energeia "activity, action, operation" (see energy). Meaning "state of being real" is from 1670s (actualities "existing conditions" is from 1660s).

Mod. use of actuality in the sense of realism, contact with the contemporary, is due to Fr. actualité, from actuel, which does not mean actual, real, but now existing, up to date. [Weekley]

1650s, "powerful in operation," from Greek energetikos "active," from energein "to work, be in action, act upon" (see energy). Of persons, "active," in English from 1796 (energetical "operative" is from c. 1600; from 1630s as "full of energy," while energical is attested from 1560s). Related: Energetically.

1751; see energy + -ize. Related: Energized; energizing.