eternal

Etymology

From Middle English eternal, from Old French eternal, from Late Latin aeternālis, from Latin aeternus (“eternal”), from aevum (“age”). Displaced native Old English ēċe.

adj

1. Lasting forever; unending.
   But here again it is another question, quite different from our having an idea of eternity, to know whether there were any real being, whose duration has been eternal. 1690, John Locke, An Essay Concerning Human Understanding
   Thy smoking altar shall be fat with food / Of incense and the grateful steam of blood; / Burnt-offerings morn and evening shall be thine, / And fires eternal in thy temple shine. 1700 [c. 1387–1400], John, transl. Dryden, “Palamon and Arcite”, in Fables, Ancient and Modern, translation of The Knight's Tale by Geoffrey Chaucer
   Organic life is nothing but a genetic mutation, an accident. Your lives are measured in years and decades. You wither and die. We are eternal. The pinnacle of evolution and existence. Before us, you are nothing. Your extinction is inevitable. We are the end of everything. 2008, BioWare, Mass Effect (Science Fiction), Redwood City: Electronic Arts, →OCLC, PC, scene: Virmire
   In a bid to understand the eternal mystery that is woman, Bart goes to the least qualified possible source for advice and counsel: his father, who remarkably seems to have made it to his mid-30s without quite figuring out much of anything. May 27, 2012, Nathan Rabin, “TV: Review: THE SIMPSONS (CLASSIC): “New Kid On The Block” (season 4, episode 8; originally aired 11/12/1992)”, in The Onion AV Club
2. (philosophy) Existing outside time; as opposed to sempiternal, existing within time but everlastingly.
3. (hyperbolic) Constant; perpetual; ceaseless; ever-present.
4. (dated) Exceedingly great or bad; used as an intensifier.
   some eternal villain

noun

1. One who lives forever; an immortal.
   Yes, I want that raw power that is only offered to the eternals or creators 2012, D. E. Phoenix, Revelations of the Fallen: The Blasphemy of Astrial Belthromoto