U
ugly, evil, hateful, and base
uncertain, questionable, erroneous, and mistaken
unctuous, shrill, brisk, and demonstrative [unctuous = exaggerated, insincere]
unhappy, unfortunate, distressed, and disastrous
uninteresting, lifeless, obscure, and commonplace
unity, aggressiveness, efficiency, and force
unkind, severe, oppressive, and callous
unpractical, childish, slipshod, and silly
unreasonable, foolish, excessive, and absurd
unrivaled, unequaled, incomparable, and matchless
upright, high-minded, brave, and liberal
urgent, important, immediate, and imperative
usage, custom, habit, and practise