U, or u, is the twenty-first letter of the English alphabet.
U may also refer to:
Science
Mathematics
- , union (set theory)
- U-set, a set of uniqueness
- U, the unitary group
Chemistry
- Uranium, symbol U, a chemical element
- u, the Dalton (unit), a unified atomic mass unit to express atomic and molecular masses
Astronomy
- U, ultraviolet magnitude, in a UBV photometric system
- U, an October 16 through 31 discovery in the provisional designation of a comet
- U (trans-Neptunian object), a possible extremely distant trans-Neptunian object
Computing
<u>
, a now-deprecated HTML element denoting underlined text- U, representing 1.75" as the minimal height of a rack unit
- U, representing a 10x10x10cm CubeSat
- U, universal Turing machine
Biology
- U, abbreviation for uracil
- U, mitochondrial haplogroup U
Other scientific uses
- U, a common notation for potential energy
- U, the middle of an edge joining a hexagonal and a square face of the Brillouin zone of a face-centered cubic lattice, in solid-state physics
- U, one of the two subcarrier-modulated color-difference channels in the YUV colorspace, in video
- U, the recommended symbol for a system's internal energy, in thermodynamics
- U, units, any of various standard units of biological activity, such as insulin units, enzyme units, or penicillin units
- U, the enzyme unit
- International units, for which the symbol U is sometimes used
- U, the abbreviation for selenocysteine, an uncommon amino acid containing selenium
- u, the alternative abbreviation for the SI prefix "micro-" when the Greek letter mu (μ) is not available
- U or U-value, the symbol for the overall heat transfer coefficient or thermal transmittance
Transportation
- U Line, also known as the Uijeongbu Line, a light metro line in Seoul
- Transilien Line U, a line of the Paris transport network
- U (Los Angeles Railway), a former streetcar line in Los Angeles
- Yurikamome, an automated guideway line in Tokyo, labeled
- The official West Japan Railway Company service symbol for:
Music
- ’u’, the first opera in the Klingon language
- "U" (Kendrick Lamar song), 2015
- "U" (Super Junior song), 2006
- U (Incredible String Band album), 1970
- U (NiziU album), 2021
- U (Tourist album), 2016 album by Tourist
- "U", a song by KNK from Remain
- "U", a song by Pearl Jam on their album Lost Dogs
- "U", a song by Stray Kids on their mixtape Hop
- "U", a song by S.E.S., released in 2002
- "U", an album by The Enid, released in 2019
- "U", a song by Treasure (band), released in 2022
People
- An honorific used in Burmese names
- An alternative spelling of Woo (Korean surname), including a list of people with that family name
- An alternative spelling of Woo (Korean given name), including a list of people with that given name
- U of Goryeo (1363–1389), king of Goryeo (Korea), often called King Woo
Places
- U, Federated States of Micronesia
- Ü-Tsang, one of three historical provinces of Tibet
- Ü (region), a particular region of Ü-Tsang
Language
- /u/, the close back rounded vowel in the International Phonetic Alphabet
- U language, a language spoken by about 40,000 people in the Yunnan Province of China
- U (cuneiform), a cuneiform sign
- U (Cyrillic), a letter of the Cyrillic script
- U (kana), a Japanese syllabary symbol
- U and non-U English, sociolectal varieties of British English
- Ս, glyph for the Armenian letter se
- u, an abbreviation for "you" in computer chats
- U-, a prefix used for German submarines during World War II
- U, a title roughly equal to "Mister" in Burmese
- The Greek letter μ
Film and television
- U (film), a 2006 French animated feature film directed by Serge Elissalde and Grégoire Solotareff
- The U (film), a 2009 documentary about the Miami Hurricanes football team
- U (Universal), a media content rating used in the following countries:
- United Kingdom, issued by the British Board of Film Classification
- India, issued by the Central Board of Film Certification
- Malaysia, issued by the Film Censorship Board of Malaysia
- France, documented at Censorship in France
- India, Latvia, Malta, Mauritius and Slovakia, documented at Motion picture content rating system and Television content rating system
- U (TV channel), a former television channel in New Zealand
- U, the production code for the 1965 Doctor Who serial The Myth Makers
- The American Spanish-language network Univisión has the U logo
- U (streaming service), (formerly UKTV Play) a free British streaming service owned by UKTV
Other uses
- University, commonly abbreviated "U"
- U Mobile, Malaysian mobile phone and data service provider
- U-bend, a U-shaped plumbing trap
- U-bolt, a U-shaped metal fastener
- Ⓤ, (U inside a circle), hechsher or kosher certification by the Orthodox Union
- U, =U= or -U-, symbol for Ustaše Croatian movement
- Nickname for football teams:
- La U or Universitario de Deportes, Peru
- Universitatea Cluj, Romania
- U, the color blue in Magic: The Gathering
- Wii U, the sixth Nintendo video game home console, released in 2012
- Uniform, the military time zone code for UTC−08:00
- "U" Is for Undertow, the twenty-first novel in Sue Grafton's "Alphabet" mystery series, published in 2009
- Underscore, originally invoked in HTML using <u>
- U, a brand of menstrual hygiene products by Kotex
- U, the logo for Unilever
See also
Topics referred to by the same term This disambiguation page lists articles associated with the title U.If an internal link led you here, you may wish to change the link to point directly to the intended article. Category: