UMPIRE—referee, arbitrator, judge, arbiter.
UNANIMITY—accord, agreement, unity, concord. (Discord.)
UNBRIDLED—wanton, licentious, dissolute, loose.
UNCERTAIN—doubtful, dubious, questionable, fitful, equivocal, ambiguous, indistinct, fluctuating.
UNCIVIL—rude, discourteous, disrespectful, disobliging. (Civil.)
UNCLEAN—dirty, foul, filthy, sullied. (Clean.)
UNCOMMON—rare, strange, scarce, singular, choice. (Common, ordinary.)
UNCONCERNED—careless, indifferent, apathetic. (Anxious.)
UNCOUTH—strange, odd, clumsy. (Graceful.)
UNCOVER—reveal, strip, expose, lay bare. (Hide.)