| Abbreviation | Definition |
|---|---|
| UN | Uneducated Nations |
| UN | United Nothing |
| UN | United Nuzum |
| UN | Unmistakably Nutless |
| UN | Unwanted Nobodies |
| UN | Useless Nations |
| UN | Useless Nutless |
| UN | Useless Nuts |
| UN | Usually Nothing |
| UNA | Uchronic Nerd Alliance |
| UNA | Use No Abbreviations |
| UNC | United Nations of Carolina |
| UNC | University of National Champions |
| UNC | University of No Class |
| UNC | University of No Confidence |
| UNC | Usual Nest of Commies |
| UND | Unidentified North Dakotans |
| UNF | Uncle Ned's Female |
| UNF | University of North Fairbanks |
| UNF | University of North Floriduh |