æon, eon
(ˈiːən, ˈiːɒn)
[a. L. æōn, a. Gr. αἰών age.]
1. a. An age of the universe, an immeasurable period of time; the whole duration of the world, or of the universe; eternity.
| 1647 H. More Song of Soul Notes 136/1 For such is the nature of æon or Eternity. 1765 Tucker Lt. of Nat. I. 650 He shall endure, not simply to the aion, that is, ‘for ever,’ but to the aion of aions. 1831 Carlyle Sart. Res. (1858) 157 The mysterious Course of Providence through æons of æons. 1857 H. Miller Test. Rocks iii. 147 The protracted eons of the Carboniferous period. 1879 Farrar St. Paul I. 598 The last great æon of God's dealing with mankind. |
b. attrib. and Comb.
| 1916 O. Sitwell in E. & O. Sitwell 20th Cent. Harlequinade 25 From far within his æon-battered brain Well up those wanton wistful images. 1923 Blackw. Mag. July 61/3 The aeon-long passage of water a-down the rock has worn its surface to a glassy smoothness. 1938 W. de la Mare Memory 29 A storm-cock shrilled its aeon-old refrain. 1948 E. Sitwell Notebk. W. Shakes. vi. 53 In one of the most terrible aeon-moments of the play. |
2. The personification of an age. In Platonic Philos., A power existing from eternity; an emanation, generation, or phase of the supreme deity, taking part in the creation and government of the universe.
| 1647 H. More Song of Soul Notes 138/1 But Intellect or æon hath in himself proper Intellectuall life. 1678 Cudworth Intell. Syst. 212 The next considerable appearance of a multitude of self-existent deities seems to be in the Valentinian Thirty Gods and æons. 1865 Lecky Rationalism I. iii. 228 More commonly she was deemed a personification of a Divine attribute, an individual æon. |
3. Geol. Usu. eon. The largest division of geological time, composed of several eras.
| 1933 Schuchert & Dunbar Textbk. Geol. (ed. 3) v. 70 It has recently been proposed to use the name Cryptozoic eon..for Pre-Cambrian time, and Phanerozoic eon..for all subsequent time. 1958 [see cryptozoic a. 2]. 1969 Proc. Geol. Soc. Lond. Aug. 148 Eon, compounded of several eras. 1980 Eicher & McAlester Hist. of Earth ii. 48 The last 15 percent of geologic history is known as the Phanerozoic..Eon. 1982 W. B. Harland et al. Geologic Time Scale ii. 7/2 The classification has developed traditionally on a hierarchical basis with eons (e.g. Phanerozoic), eras (e.g. Mesozoic), periods (e.g. Jurassic), [etc.]. |
4. Geol. and Astr. One thousand million years.
| 1968 R. A. Lyttleton Mysteries Solar Syst. i. 5 We are now fairly certain that the planets have existed for something like 4 to 5 thousand million years, four to five aeons (to use a modern unit of time, the aeon, which avoids the confusion associated with the word billion). 1969 G. G. Simpson in F. W. Preston et al. Diversity & Stability in Ecol. Systems v. 165 These fossils are with considerable probability somewhat but not greatly older than the long-known and classical faunas universally recognized as early Cambrian. Their age may be on the order of 0·7 eon (700 million years). 1974 Nature 15 Mar. 199 (heading) Evidence for a ∼4·5 aeon age of plagioclase clasts in a lunar highland breccia. |