- unendurably
- unexceeded
- unexcelled
- unfitting
- unfalteringly
- unwavering will
- undeviating
- uninvitedly
- unshakeable
- unwantedly
- unmarketable
- undutifulness
- unflickering
- unflinchingly
- unintoxicated
- unconfessed
- unshuttered
- unconfined
- unconditioned
- unconjugate bilirubin
- unconscious
- unconscionable
- unpolluted
- uncontaminated
- uncontrollable
- uncorrectable
- unconventional
- unrebuked
- unmanageable
- ungovernable
- unreproved
- unnotified
- uninfluenced
- untinged
- unimpressed
- undeviated
- undismayed
- untasted
- unshaken
- untouched: unpolluted
- untouched
- unmoved
- unmoving
- unimposing
- unimpressive
- unvindictive
- unviable
- unequivocally
- urachus
- uraemic pneumonitis