αἰών

αἰών (aion, "eye-OWN") is the Greek word for a lifetime, a long stretch of time, an age — and, later, eternity. The record gives it 982 occurrences across 107 works, and its heartland is unmistakably the religious and the metaphysical. It lives most densely in the Psalms (Psalmi, 200), then in the Enneads (73), Daniel (LXX, 59), the Odes (Odae, 51), Sirach (Siracides, 48), and the Psalms of Solomon (Psalmi Salomonis, 34). This is a word of prayer and of philosophy — sung "unto the age" in the Greek scriptures, thought through as time-itself.

The lexica agree on the arc from life to eternity. Beekes (Etymological Dictionary of Greek, Brill 2010) glosses it "(life)time, long period of time, eternity," and records the adverb αἰέν (aien, "always") and the derived adjective αἰώνιος (aionios, "enduring, eternal"). Frisk (Griechisches etymologisches Wörterbuch, 1960–72) gives the German equivalents "Leben(szeit) … Ewigkeit" — "lifetime … eternity." Chantraine (Dictionnaire étymologique de la langue grecque, 1968–80) argues the primary sense is "force vitale" — "vital force," life — reading it beside ψυχή (psychē, "soul") in Homer's ψυχή τε καὶ αἰών (psychē te kai aiōn, "soul and life," Iliad 16.453), and notes the word is masculine but sometimes feminine, perhaps by analogy with ψυχή. LSJ (Liddell–Scott–Jones, 1940) opens with "period of existence," citing Aristotle, and runs the sense from lifetime and life to eternity.

On the deep root the record points but does not resolve. Etymology pointers are matched in Beekes (s.v. αἰών, pp. 93–94, with reconstructed candidates *afaiwp-, *afaj-), in Chantraine, and in Frisk — three authorities treating the word, without a single settled derivation stated here. The cited surfaces cluster in 1 Corinthians and stand in the oblique cases — αἰών reaching, across the New Testament, from this age to the ages to come.

If the same word names both a single breath of life and the endless age, where does the one become the other?