- unsound
- unbalanced
- unsightly
- unequal
- unprincipled
- ulcer
- unadorned
- unburden
- uncivil
- uncommon
- undergrowth
- understate
- unpalatable
- undoubtedly
- unfathomable
- unnerve
- uninspired
- unforgivable
- unhappy
- upbeat
- up-and-coming
- up to scratch
- unworthily
- utterance
- unworldly
- unwonted
- unwitting
- unwind
- unwillingfulness
- unwieldy
- unwarranted
- unvarnished
- unused
- untrustworthy
- untiring
- unthinkable
- unsurprising
- unsteady walk
- unsteady
- unspeakably
- unskillfullness
- unshaken
- unshakeable
- unsettled
- unseat
- unsafe
- unruly
- unrequited
- unreliable
- unreal
- unreadable
- unqualified
- unprofessional
- unpreparedness
- unprepared
- unpremeditated
- unprecedented
- utilize
- unplaced
- unmentionable
- unmanageable
- unmake
- unlike
- usurp
- unlearn
- universally
- usurious interest
- united
- unitary system
- unique
- usufruct
- uninviting
- uninterrupted
- unintelligible
- uninhibited
- uninhabited
- unimportant
- unimpeachable
- unimaginative
- uniform
- unified field
- unhoped for
- unholy
- unheard of
- unguarded
- ungainly
- unfortunately
- unfortunate woman
- unfortunate
- unflagging
- unfeigned
- unfeeling
- unfasten
- usher something in, mark the start of
- unexceptional
- unethical
- unequivocal
- useful
- unenthusiastic
- unemployed