| unwieldy | difficult to carry or move because of its size, shape, or weight | |
| untoward | Unexpected and inappropriate or inconvenient | |
| untenable | Not able to be maintained or defended against attack or objection | |
| unsavory | Disagreeable to taste, smell, or look at | |
| unruly | Disorderly and disruptive and not amenable to discipline or control | |
| unpropitious | Not giving or indicating a good chance of success; unfavorable | |
| unpretentiousness | The quality of being modest and not claiming to be important | |
| unkempt | Having an untidy or disheveled appearance | |
| uniform | Remaining the same in all cases and at all times; unchanging in form or character | |
| undulate | To move with a smooth wavelike motion | |