| Unionist | unionist |
| Unionistin | unionist |
| Zionist | Zionist |
| Unittest | unit test |
| Union | union |
| Kantonist | cantonist |
| Kolonist | colonist |
| Mennonist | Mennonite |
| Chronist | chronicler |
| Hedonist | hedonist |
| Leninist | Leninist |
| Onanist | masturbator onanist wanker |
| Pianist | pianist |
| Uranist | uranist |
| Animist | animist |
| Unisono | unison |
| unisono | unisonous |
| Unixzeit | Unix time |
| Unbiunium | unbiunium |
| Unikat | one of a kind |