| Unterdeck | lower deck |
| Unterwerk | substation |
| Unterdruck | depression low pressure partial vacuum underpressure |
| Unterrock | petticoat slip half slip underskirt |
| Hinterdeck | afterdeck |
| unterdrückt | downtrodden |
| unterer | lower |
| Unterhemd | undershirt |
| Unterleib | abdomen alvus |
| Untermenü | submenu |
| Unterwelt | underworld nether world netherworld |
| unterwegs | on the way on the road |
| Wetterdeck | weather deck |
| Achterdeck | afterdeck quarterdeck |
| Oberdeck | weather deck |
| Verdeck | cover bridge |
| Runterweg | descent |
| Unterdrücker | oppressor |
| Unterkleid | slip |
| Untermenge | subset |