Latin word aeternus comes from Proto-Indo-European *h₂ey-, Proto-Indo-European *h₂eyu-, and later Proto-Italic *aiwom (Age.)
| Dictionary entry | Language | Definition |
|---|---|---|
| *h₂ey- | Proto-Indo-European (ine) | |
| *h₂eyu- | Proto-Indo-European (ine) | |
| *h₂ey-u- | Proto-Indo-European (ine) | |
| *aiwo- | Proto-Italic (itc-pro) | |
| *aiwom | Proto-Italic (itc-pro) | Age. |
| aivom | Old Latin (itc-ola) | Age. Time, lifetime. |
| aevom | Latin (lat) | |
| aetatis | Latin (lat) | |
| aeviternum | Latin (lat) | |
| aeternus | Latin (lat) | Eternal, endless. Immortal. Permanent, lasting, perpetual. |