| Unstable subatomic particles | 28 |
| Unstable symptom of nerves | 26 |
| Unstable, metaphorically | 24 |
| Unsteady on one's feet | 26 |
| Unsteady walker, maybe | 22 |
| Unsteady, as a relationship | 27 |
| Unsteady, as from old age | 25 |
| Unstimulating position | 22 |
| Unstoppable determination | 25 |
| Unstoppable, as a plan | 22 |
| Unstrained quality, to Portia | 29 |
| Unstressed midcentral vowel | 27 |
| Unstressed vowel sound | 22 |
| Unstressed vowel sounds | 23 |
| Unstressed vowel symbol | 23 |
| Unsubstantiated theories? | 25 |
| Unsuccessful '50s Ford | 26 |
| Unsuccessful 1957 debut | 23 |
| Unsuccessful contenders | 23 |
| Unsuccessful invader of India | 29 |
| Unsuccessful liquor buyers | 26 |
| Unsuccessful participant | 24 |
| Unsuccessful performance | 24 |
| Unsuccessful trophy seeker | 26 |
| Unsuccessful, as a mission | 26 |
| Unsuccessful, as batters | 24 |
| Unsuitable for mixed company | 28 |
| Unsuitable for parades | 22 |
| Unsuitable for surgery | 22 |
| Unsuitable for the kids | 23 |
| Unsure "Uh-uh" | 24 |
| Unsurpassed up to the present | 29 |
| Unsurpassed, as in sports | 25 |
| Unsurpassingly unoriginal | 25 |
| Unswerving in allegiance | 24 |
| Unswervingly committed | 22 |
| Untainted by corruption | 23 |
| Untamable mass of hair | 22 |
| Untellable to Washington | 25 |
| Unter ___ Linden, in Berlin | 27 |
| Untermeyer book: Abbr. | 22 |
| Unthinking, superficial sort | 28 |
| Unthreatening, as threats | 25 |
| Untidy, disordered condition | 28 |
| Until the end of a pregnancy | 28 |
| Until the end, as a pregnancy | 29 |
| Until the very last moment | 26 |
| Until the ____ come home | 24 |
| Until you get it right | 22 |
| Untoppable gymnastics scores | 28 |
| Untouchable crimefighter | 24 |
| Untouchable tennis serves | 25 |
| Untouchable's belief | 24 |
| Untouchable, in mafia lingo | 27 |
| Untouchables leader Ness | 24 |
| Untouchables, for example | 25 |
| Untraceable author, for short | 29 |
| Untraceable, for short | 22 |
| Untreated, he's tricky | 26 |
| Untrue version of the truth | 27 |
| Untrustworthy poker player | 26 |
| Untwist a ship's rope | 25 |
| Unusable, as a cellphone | 24 |
| Unusual astronomical event | 26 |
| Unusual belly protrusion | 24 |
| Unusual objet d'art | 23 |
| Unusual perception, for short | 29 |
| Unusual shoebox marking | 23 |
| Unusual sighting, for short | 27 |
| Unusual, as a vacation | 22 |
| Unusual, in Caesar's day | 28 |
| Unusually good 365 days | 23 |
| Unusually large or heavy | 24 |
| Unusually large, as clothing | 28 |
| Unusually narrow shoe size | 26 |
| Unusually narrow, in a way | 26 |
| Unuttered 'Ah, me' | 26 |
| Unuttered 'Alas' | 24 |
| Unuttered 'Why me?' | 27 |
| Unvarnished telling of events | 29 |
| Unvarying background sound | 26 |
| Unveil, with "out" | 28 |
| Unveiling response, perhaps | 27 |
| Unwanted "gift" | 25 |
| Unwanted aquarium collection | 28 |
| Unwanted aquarium organism | 26 |
| Unwanted auto accessory? | 24 |
| Unwanted check from the govt. | 29 |
| Unwanted china shop visitor? | 28 |
| Unwanted classification, once | 29 |
| Unwanted computer message | 25 |
| Unwanted Facebook followers | 27 |
| Unwanted fungus in the fridge | 29 |
| Unwanted garden growth | 22 |
| Unwanted guest in a pantry | 26 |
| Unwanted hair conditions | 24 |
| Unwanted Hamelin resident | 25 |
| Unwanted in-box filler | 22 |
| Unwanted kitchen visitor | 24 |
| Unwanted letter of fiction | 26 |