English Words: U
23,789 words · Page 1 of 476
The twenty-first letter of the English alphabet, called u and written in the Latin script.
Initialism of unaccompanied alien child: a child sent to cross an international border without a formal adult guardian.
Initialism of unrecoverable application error (the standard Microsoft Windows error message in Win16)
Initialism of uncrewed aerial system, unmanned aerial system, uncrewed aircraft system, or unmanned aircraft system: an aircraft with no onboard pilot, and sometimes completely unpiloted, as well as the other components of the system, including automated guidance and telemetry, a remote operator if any, etc.
Initialism of unmanned aerial vehicle or uncrewed aerial vehicle: an aircraft with no onboard pilot, and sometimes completely unpiloted, that is capable of controlled, sustained, level flight.
Any of a class of small protein, or polypeptide, present in the cells of all eukaryotes, that play a part in modifying and degrading proteins.
The state or quality of being, or appearing to be, everywhere at once; actual or perceived omnipresence.
An organ formed of the mammary glands of female quadruped mammals, particularly ruminants such as cattle, goats, sheep and deer.
A Lezgic language (Northeast Caucasian) spoken by the Udi people who live mostly in Azerbaijan and nearby regions. Probably descended from Caucasian Albanian.
Spelling & Dictionary Insight
The English alphabetical index for the letter U contains 23,789 headwords drawn from our Wiktionary-derived dictionary table. At 50 entries per page the browse splits into 476 pages, and you are currently viewing page 1. Every row above is a dictionary-backed entry with a canonical slug, and each links through to a full definition page with pronunciation, senses, etymology, and related-word data where available.
On this page 50 of 50 entries carry a part-of-speech tag and 50 carry at least one stored definition. Coverage varies across letters because Wiktionary volunteers build entries at different speeds for different parts of the alphabet, letters with common starting sounds (S, C, T, P) usually have the densest coverage, while less frequent starters (X, Q, Z) tend to have shorter but more specialised lists. PlainSpell surfaces whatever data is present and links back to the source when a definition is not yet recorded.
For readers using this index as a spelling reference, the guarantee is that every form you see on the list is a documented English headword, not a guess, not a derived inflection lacking a lemma row. If a word you expected to find is absent from the "U" list, it usually means the form exists only as an inflection of another lemma (e.g. a past participle stored under the infinitive) or the entry has not yet been imported from Wiktionary. Use the search bar or the misspelling lookup to resolve these cases.