J (disambiguation)

J is the tenth letter of the Latin alphabet.

J may also refer to:

• Palatal approximant in the International Phonetic Alphabet
• J, Cyrillic letter Je

Astronomy

• J, a provisional designation prefix for some objects discovered between May 1 and 15 of a year

Computing

• J (programming language), successor to APL
• J# programming language for the Microsoft .NET Framework
• J (text editor), written in Java
• J operator, 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 (Y-DNA)
• ATC code J Antiinfectives for systemic use, a section of the Anatomical Therapeutic Chemical Classification System

Mathematics

• J, symbol in the Bessel function
• j, the second imaginary unit of a quaternion
• j, an index variable in a matrix
• The j-invariant, a modular function

Physics

• Joule, the SI unit of energy
• Current density
• Second moment of area
• j, the imaginary unit ($\sqrt{-1}$) in fields where i is traditionally used for another value
• J, name given by Samuel C. C. Ting for the J/ψ particle
• J-coupling, indirect dipole-dipole coupling between two nuclear spins

Music

• J (Japanese musician), a Japanese rock musician, guitarist and singer
• J (Korean singer), a Korean pop singer
• J., nickname of American White Zombie guitarist Jay Yuenger
• J Mascis, American singer and guitarist of Dinosaur Jr.
• J Records, a record label

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

Film and television

• Agent J, a character in the Men in Black films portrayed by Will Smith
• J, an antagonist in Bobobo
• Kamen Rider J, a Japanese movie

Other uses

• J, slang for joint (cannabis)
• J, slang for Air Jordan shoes
• J, slang for a jump shot in basketball
• J band, radio frequencies ranges from 10 to 20 GHz
• J (psychedelic), an entactogenic drug
• J (New York City Subway service)
• J Church, a light rail line in San Francisco
• Elgin, Joliet and Eastern Railway, a Chicago railway sometimes referred to as "The J"
• J, the international license plate code for Japan
• J, the Canadian postal code for the western and northern regions of Quebec
• J, German mint mark 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., a weekly newspaper serving the Jewish community in Northern California
• J, the narrator of Jerome K. Jerome's novel Three Men in a Boat
• J., Jezper Söderlund, the trance artist
• Lamborghini Aventador J, a 2012 Lamborghini supercar
• J (novel), a 2014 novel by Howard Jacobson

See also

• J/22, J/24 and J/80 sailboat classes
• J Mays, Group Vice President of Design and Chief Creative Officer at Ford Motor Company
• J Dilla, a hip-hip performer and producer
• Jay-Z, a hip-hop performer
• Jay, bird
• Jay Jay, 2003 film
• JJJ (disambiguation)