- unidimensional
- upper arm length
- upon one's guard
- upper hand
- upper berth
- upper limb
- uppercut
- undercarriage
- underbody
- unkind person
- united states president
- unimproved
- undisguised
- unsegmented
- undivided
- unimpaired
- unkept
- unsuited
- unsplit
- unshared
- unpartitioned
- underprivileged
- unleaded gasoline
- unleaded petrol
- ungainly controversy
- United Society of Believers in Christ's Second Appearing
- up sticks
- unpackaged
- unfurl
- United States Army Rangers
- underbid
- underground treasure
- united states secret service
- unilateralist
- unilateral synchronization system
- UNIX guru
- ungallantly
- unicorn
- urography
- urological examination
- unfeelingness
- unsanded
- undiluted
- unwithered
- upland white aster
- upland sandpiper
- upland plover
- unilateral paralysis
- uncouthly
- uvwxy lemina