Romanian word uniune comes from Proto-Indo-European *yo-, Proto-Indo-European *oynolos, and later Proto-Italic *oinos (One.)
| Dictionary entry | Language | Definition |
|---|---|---|
| *yo- | Proto-Indo-European (ine-pro) | |
| *oynolos | Proto-Indo-European (ine-pro) | |
| *ínos | Proto-Indo-European (ine-pro) | |
| *oinos | Proto-Italic (itc-pro) | One. |
| oinos | Old Latin (itc-ola) | (cardinal) one. |
| unus | Latin (lat) | Alone. One, single (cardinal) one; 1 (Medieval Latin) a, an. |
| unionis | Latin (lat) | |
| uniune | Romanian (ron) | Union, connection, association, alliance. |