J is the tenth letter of the Latin alphabet. J may also refer to: *

Palatal approximant The voiced palatal approximant, or yod, is a type of consonant used in many spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is . The equivalent X-SAMPA symbol is j, and in the Americanist phonetic no ...

in the International Phonetic Alphabet * J, Cyrillic letter Je

Astronomy

* J, a

provisional designation Provisional designation in astronomy is the naming convention applied to astronomical objects immediately following their discovery. The provisional designation is usually superseded by a permanent designation once a reliable orbit has been cal ...

prefix for some objects discovered between May 1 and 15 of a year

Computing

J (programming language) The J programming language, developed in the early 1990s by Kenneth E. Iverson and Roger Hui, is an array programming language based primarily on APL (also by Iverson). To avoid repeating the APL special-character problem, J uses only the basi ...

, successor to APL * J# programming language for the Microsoft .NET Framework *

J operator In computer science, Peter Landin's J operator is a programming construct that Function composition, post-composes a Lambda (programming), lambda expression with the continuation to the current lambda-context. The resulting “function” is first ...

, a programming construct * J (operating system), an operating system for ICL's System 4 series of computers

Genetics and medicine

Haplogroup J (mtDNA) Haplogroup J is a human mitochondrial DNA (mtDNA) haplogroup. The clade derives from the haplogroup JT, which also gave rise to haplogroup T. In his book ''The Seven Daughters of Eve'', Bryan Sykes named the originator of this mtDNA haplogroup ...

Haplogroup J (Y-DNA) Haplogroup J-M304, also known as J, ISOGGbr> ''Y-DNA Haplogroup J and its Subclades - 2016'' (2 February 2016). is a human Y-chromosome DNA haplogroup. It is believed to have evolved in Western Asia. The clade spread from there during the Neo ...

* ATC code J ''Antiinfectives for systemic use'', a section of the Anatomical Therapeutic Chemical Classification System

Mathematics

* J, symbol used to denote the

Bessel function Bessel functions, first defined by the mathematician Daniel Bernoulli and then generalized by Friedrich Bessel, are canonical solutions of Bessel's differential equation x^2 \frac + x \frac + \left(x^2 - \alpha^2 \right)y = 0 for an arbitrary ...

* ''j'', used as the symbol for the

imaginary unit The imaginary unit or unit imaginary number () is a solution to the quadratic equation x^2+1=0. Although there is no real number with this property, can be used to extend the real numbers to what are called complex numbers, using addition an ...

(

\sqrt

) in fields where ''i'' is used for a different purpose (such as electrical current) * ''j'' and ''j²'' (or

\bar

) are also used for the complex cube

roots of unity In mathematics, a root of unity, occasionally called a de Moivre number, is any complex number that yields 1 when raised to some positive integer power . Roots of unity are used in many branches of mathematics, and are especially important in ...

* ''j'', a number with the property ''j'' ² = +1, used in the definition of the split-complex numbers * ''j'', the second imaginary unit of a

quaternion In mathematics, the quaternion number system extends the complex numbers. Quaternions were first described by the Irish mathematician William Rowan Hamilton in 1843 and applied to mechanics in three-dimensional space. Hamilton defined a quatern ...

* , an index variable in a

matrix Matrix most commonly refers to: * ''The Matrix'' (franchise), an American media franchise ** ''The Matrix'', a 1999 science-fiction action film ** "The Matrix", a fictional setting, a virtual reality environment, within ''The Matrix'' (franchis ...

* The

j-invariant In mathematics, Felix Klein's -invariant or function, regarded as a function of a Complex analysis, complex variable , is a modular function of weight zero for defined on the upper half-plane of complex numbers. It is the unique such funct ...

, a modular function

Physics

* J,

Joule The joule ( , ; symbol: J) is the unit of energy in the International System of Units (SI). It is equal to the amount of work done when a force of 1 newton displaces a mass through a distance of 1 metre in the direction of the force applied ...

, the SI unit of energy * J, the SI-recommended dimension symbol for

luminous intensity In photometry, luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human e ...

, conventionally rendered in a sans-serif typeface * ,

current density In electromagnetism, current density is the amount of charge per unit time that flows through a unit area of a chosen cross section. The current density vector is defined as a vector whose magnitude is the electric current per cross-sectional ar ...

second moment of area The second moment of area, or second area moment, or quadratic moment of area and also known as the area moment of inertia, is a geometrical property of an area which reflects how its points are distributed with regard to an arbitrary axis. The ...

* J, name given by Samuel C. C. Ting for the J/ψ particle *

J-coupling In nuclear chemistry and nuclear physics, ''J''-couplings (also called spin-spin coupling or indirect dipole–dipole coupling) are mediated through chemical bonds connecting two spins. It is an indirect interaction between two nuclear spins that ...

, indirect dipole-dipole coupling between two nuclear spins

Music

* J, stage name of Jang Ye-eun, a member of the K-Pop group

STAYC STAYC (; , acronym for Star to a Young Culture) is a South Korean girl group formed by High Up Entertainment. The group is composed of six members: Sumin, Sieun, Isa, Seeun, Yoon, and J. They debuted on November 12, 2020, with the release of t ...

J (Korean singer) Chung Jae-young (; born May 2, 1977), better known by the stage names J and J.ae (), is a Korean-American singer based in South Korea. She debuted in 1998 with the album, ''J: Gold''. Early life J grew up in San Francisco, California, and late ...

, a Korean pop singer *

J (musician) , better known by his stage name J, is a Japanese musician, singer, songwriter and record producer. He is best known as bassist and co-founder of the rock band Luna Sea since 1986. After they disbanded in 2000 he focused on his solo career, for ...

, a Japanese rock musician * J., nickname of American White Zombie guitarist

Jay Yuenger Jay Noel Yuenger (born December 26, 1966), also known by the stage name "J.", is a rock guitarist best known for his work with Grammy-nominated heavy metal band White Zombie. Music career As a teenager, Yuenger's interests quickly progressed ...

*J., stage name of German musician

Jaye Muller Jaye Muller (born Jens Müller) is a German musician and Internet entrepreneur who performed under the name J., and later in a duo named "Muller and Patton" with American musician Ben Patton and under the name "Count Jaye" (since 2015). In 1992, ...

J Mascis Joseph Donald Mascis Jr. ( ; born December 10, 1965), better known as J Mascis, is an American musician who is the singer, guitarist and main songwriter for the alternative rock band Dinosaur Jr. He has also released several albums as a solo art ...

, American singer and guitarist of Dinosaur Jr. *

J Records J Records was an American record label owned and operated by Bertelsmann Music Group until it was transferred to Sony Music Entertainment when they acquired all of BMG’s record labels in late 2008. It was distributed through the RCA Music Gro ...

, a record label

Albums

* J, album by Lazza

List of number-one hits of 2020 (Italy) This is a list of the number-one hits of 2020 on Italy's Singles and Albums Charts, ranked by the Federazione Industria Musicale Italiana (FIMI). Chart history See also * 2020 in music * List of number-one hits in Italy References {{FIMI ...

Songs

* "J", song by Reggie and the Full Effect from the album '' Last Stop: Crappy Town'' * "J", song by Mindless Self Indulgence from the album ''

Frankenstein Girls Will Seem Strangely Sexy ''Frankenstein Girls Will Seem Strangely Sexy'' is the second studio album by New York City band Mindless Self Indulgence released in 2000. The album is the follow-up to the album ''Tight''. This is the last studio album to feature Vanessa YT on ...

Film and television

Agent J Agent J (usually called J), originally James Darrell Edwards III, is one of the two protagonists of the ''Men in Black'' film series. Born October 19, 1965, Jay is an agent of the MiB, recruited by Agent K. He is energetic, and tries to bring li ...

, a character in the ''Men in Black'' films portrayed by Will Smith * J, an antagonist in ''

Bobobo is a Japanese comedy manga series written and illustrated by Yoshio Sawai. It was serialized in Shueisha's Shōnen manga, ''shōnen'' manga magazine ''Weekly Shōnen Jump'' from February 2001 to November 2005, with its chapters collected in ...

'' * ''

Kamen Rider J (''Masked Rider J'') is a 1994 Japanese tokusatsu superhero movie produced by Toei Company and loosely based on their ''Kamen Rider'' Series. It was the final story in which Shotaro Ishinomori was involved, who died 4 years later. As part of ...

'', a Japanese movie *J, the production code for the 1964 ''Doctor Who'' serial ''

Planet of Giants ''Planet of Giants'' is the first serial of the second season in the British science fiction television series ''Doctor Who''. Written by Louis Marks and directed by Mervyn Pinfield and Douglas Camfield, the serial was first broadcast on BBC1 i ...

Writers

* J (sometimes given as I), pen name of the Danish novelist Cornelia von Levetzow (1836–1921)

Transport

J (Los Angeles Railway) J was a streetcar line in Los Angeles, California. It was operated by the Los Angeles Railway from 1911 to 1945, by Los Angeles Transit Lines from 1945 to 1958, and by the Los Angeles Metropolitan Transit Authority from 1958 to 1963. History ...

J (New York City Subway service) The J Nassau Street Local and Z Nassau Street Express are two rapid transit services in the B Division of the New York City Subway. Their route emblems, or "bullets", are colored since they use the BMT Nassau Street Line in Lower Manhattan. ...

* J Church (San Francisco Muni) *

J Line (Los Angeles Metro) The J Line (formerly the Silver Line, sometimes listed as Line 910/950) is a bus rapid transit route that runs between El Monte, Downtown Los Angeles and Gardena, with some trips continuing to San Pedro. It is one of the two lines in the M ...

* NZR J Class, a 4-8-2 type class of steam locomotive used by New Zealand Railways

Other uses

* J, slang for

joint (cannabis) A joint (), also commonly referred to as a "doobie" or "doob", is a rolled cannabis cigarette. Unlike commercial tobacco cigarettes, the user ordinarily hand-rolls joints with rolling papers, though in some cases they are machine-rolled ...

* J, slang for

Air Jordan Air Jordan is an American brand of basketball shoes produced by American corporation Nike. The first Air Jordan shoe was produced for Hall of Fame former basketball player Michael Jordan during his time with the Chicago Bulls in late 1984 an ...

shoes * J, slang for a jump shot in basketball * J band (disambiguation) * J (psychedelic), an entactogenic drug *

* J Church, a light rail line in San Francisco *

Elgin, Joliet and Eastern Railway The Elgin, Joliet and Eastern Railway was a Class I railroad, operating between Waukegan, Illinois and Gary, Indiana. The railroad served as a link between Class I railroads traveling to and from Chicago, although it operated almost entirely wit ...

, a Chicago railway sometimes referred to as "The J" * J, the

international license plate code The country in which a motor vehicle's vehicle registration plate was issued may be indicated by an international licence plate country code, formerly known as an International Registration Letter or International Circulation Mark. It is ref ...

for Japan * J, the

Canadian postal code A Canadian postal code (french: code postal) is a six-character string that forms part of a postal address in Canada. Like British, Irish and Dutch postcodes, Canada's postal codes are alphanumeric. They are in the format ''A1A 1A1'', where ' ...

for the western and northern regions of Quebec * J, German

mint mark A mint mark is a letter, symbol or an inscription on a coin indicating the mint where the coin was produced. It should not be confused with a mintmaster mark which is the mark of the mintmaster. History Mint marks were first developed to locate ...

for the city of Hamburg * J abbreviation for Jahwist, one of the major authors of the Torah * J, an abbreviated title of a High Court judge (in Law Reports, etc.), e.g. Bloggs J * ''

J. The Jewish News of Northern California ''J. The Jewish News of Northern California'', formerly known as ''Jweekly'', is a weekly print newspaper in Northern California, with its online edition updated daily. It is owned and operated by San Francisco Jewish Community Publications In ...

'', a weekly newspaper serving the Jewish community in Northern California * J, the narrator of Jerome K. Jerome's novel ''

Three Men in a Boat ''Three Men in a Boat (To Say Nothing of the Dog)'',The Penguin edition punctuates the title differently: ''Three Men in a Boat: To Say Nothing of the Dog!'' published in 1889, is a humorous account by English writer Jerome K. Jerome of a tw ...

'' * J., Jezper Söderlund, the trance artist * Lamborghini Aventador J, a 2012 Lamborghini supercar * ''J'' (novel), a 2014 novel by Howard Jacobson * ''ʲ'', the symbol for Palatalization in the IPA * Juliet, sometimes used as the unofficial military time zone code for local time * '' "J" Is for Judgment'', the tenth novel in Sue Grafton's "Alphabet mystery" series, published in 1993 *

Guy Big J Guy Motors was a Wolverhampton-based vehicle manufacturer that produced cars, lorries, buses and trolleybuses. The company was founded by Sydney S. Guy (1885–1971) who was born in Kings Heath, Birmingham. Guy Motors operated out of its Falli ...

, range of trucks produced by Guy Motors of England between 1964 and 1978 * code for

academic journal An academic journal or scholarly journal is a periodical publication in which scholarship relating to a particular academic discipline is published. Academic journals serve as permanent and transparent forums for the presentation, scrutiny, and d ...

in the reference section of an academic work