- unemployment
- unexplained
- unconditional
- unconcealed
- unsubtle
- uncharged
- urbanised
- urbanized
- unconsciousness
- unfeathered
- unexportable
- unimaginable
- uranologist
- unenergetically
- uninstructive
- uneducated person
- urbanity
- urban compost
- understandable
- upchuck
- unseemliness
- under full sail
- uncompassionate
- user defined word
- user defined function
- uninstructed
- unproved
- user interface
- unscientific
- untrue (person)
- union member
- unionism
- unfamiliarity
- used as a suffix to mean fortunate
- undershoot
- untitled
- update
- unorthodox
- unwitnessed
- unstated
- unsaid
- unfortunate person
- unlettered person
- urology
- unenergetic
- uranographer
- unusualness
- usualness
- unladylike
- used as a suffix with nouns to mean impregnated