N is the fourteenth letter of the Latin alphabet. N or n may also refer to:

Mathematics

\mathbb

, the set of natural numbers * N, the field norm * N for ''nullae'', a rare Roman numerals#Zero, Roman numeral for zero * n, the size of a Sample (statistics), statistical sample

Science

* N for Newton (unit), the SI derived unit of force * N or

F_n

, a normal force in mechanics * Nitrogen, symbol N, a chemical element * N or Asn, the symbol for the common natural amino acid asparagine * N, the Equivalent concentration, Normality (chemistry) or chemical concentration of a solution * ''N'', the neutron number, the number of neutrons in a nuclide * N, in Brillouin zone, the center of a face of a body-centered cubic lattice * n, for nano-, prefix in the SI system of units denoting a factor of 10⁻⁹ * n, the optical refractive index of a material * n, the principal quantum number, the first of a set of quantum numbers of an atomic orbital * n, an electron density, the measure of the probability of an electron being present at a specific location * n, an amount of substance in chemical physics * n, the coordination number of a substance * ''n-'', a lowercase prefix in chemistry denoting the straight-chain form of an open-chain compound in contrast to its branched isomer * ''N-'', an uppercase prefix in chemistry denoting that the substituent is bonded to the nitrogen, as in amines * ATC code N ''Nervous system'', a section of the Anatomical Therapeutic Chemical Classification System * Haplogroup N (mtDNA), a human mitochondrial DNA haplogroup * Haplogroup N (Y-DNA), a human Y-chromosome DNA haplogroup * N band, an atmospheric transmission window in the mid-infrared centred on 10 micrometres * N ray, a hypothesized form of radiation, found to be illusory *N., abbreviation of the Latin word ''nervus'' meaning nerve, used in anatomy, e.g. Vagus nerve, N. vagus

Engineering

* N, in geotechnical engineering, the result of a standard penetration test * N, in electrical systems, the earthing system, connection to neutral * N, an ITU prefix allocated to the United States for radio and television stations * n (Poland), a digital TV platform * N battery or N cell, a standard size of dry cell battery * N connector, a threaded RF connector for joining coaxial cables

Entertainment

* N. (novella), ''N.'' (novella), a 2008 short story by Stephen King * Near (Death Note) (alias ''N''), a character in the manga series ''Death Note'' * N (video game), ''N'' (video game), a 2005 computer game * N (Pokémon), the leader and king of crime syndicate Team Plasma in the ''Pokémon'' franchise * The N, a block on the Noggin (brand), Noggin TV channel *N, the production code for the 1965 ''Doctor Who'' serial ''The Web Planet'' * ''"N" Is for Noose'', the fourteenth novel in Sue Grafton's "Alphabet mystery" series, published in 1998

Music

* N (singer), stage name of Cha Hak-yeon, leader of the South Korean boy band VIXX * N, an alias of Drew Mulholland, who recorded more often as Mount Vernon Arts Lab * N (album), ''N'' (album), a 2008 album by Norther * "N", a song by BanYa for the "Pump It Up: The Perfect Collection" music video game * "n", a song by iamamiwhoami

Language

* , the International Phonetic Alphabet symbol for a voiced alveolar nasal sound ** , , , , , , , , , , symbols representing other nasal consonants in the International Phonetic Alphabet * N (kana), a Japanese kana * Noun, a part of speech

Other uses

* N, North, one of the cardinal directions of the compass * N postcode area, the part of the London post town covering part of North London, England * ₦, the symbol for the Nigerian naira currency * N, the code used to denote vehicle registration plates of Norway * N (New York City Subway service), a service of the New York City Subway * N Judah, a Muni Metro line in San Francisco, California * N (Los Angeles Railway), a line operated by the Los Angeles Railway from 1920 to 1950 * N-class ferry, a class of small RORO ferry * N scale or N gauge, a popular model railway size * N, the identifier for the knight (chess) in algebraic notation * List of military time zones#N, November, the military time zone code for UTC−01:00