| Unterpfand | pledge |
| Unterstand | cabana refuge |
| untertan | subject |
| Untertan | subject |
| Untergang | downfall sinking decline |
| Untergrund | bedrock (geol.) subfloor subgrade (constr., tech., geol.) subsoil substrate substratum base basis footing ground base coat (paint etc.) base material surface undercoat (paint etc.) underground |
| Uferpfad | towpath |
| Unverstand | foolishness |
| Unterbühne | mezzanine |
| Unterkleid | slip |
| Untertanin | subject |
| Unterton | subharmonic |
| untergehend | setting |
| Unterarm | forearm |
| Unterart | subspecies |
| Unterbau | foundation |
| Unterfangen | undertaking |
| Unterhalt | alimony upkeep |
| Unterhaus | lower chamber lower house House of Commons |
| Unterhemd | undershirt |