| unruly | Disorderly and disruptive and not amenable to discipline or control | |
| unsavory | Disagreeable to taste, smell, or look at | |
| untenable | Not able to be maintained or defended against attack or objection | |
| untoward | Unexpected and inappropriate or inconvenient | |
| unwieldy | difficult to carry or move because of its size, shape, or weight | |
| upbraided | Criticize (someone) severely or angrily especially for personal failings | |
| urbane | Having a refined manner, courteous and sophisticated | |
| usurious | Relating to the practice of lending money at exorbitantly high rates of interest | |
| usurp | To take someone's power or property by force or without the right to do so | |
| utilitarian | Designed to be useful or practical rather than attractive | |