Look up N or n in Wiktionary, the free dictionary.

N is the fourteenth letter of the English alphabet.

N or n may also refer to:

Mathematics

• ${\displaystyle \mathbb {N} }$ or N, the set of natural numbers
• N, the field norm
• N for nullae, a rare Roman numeral for zero
• n, the size of a statistical sample

Science

• 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. N. vagus

Quantities and units

• N for Newton (unit), the SI derived unit of force
• N or ${\displaystyle F_{n))$, 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 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, the physical quantity "rotation" in the International System of Quantities
• 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

Transport

• 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
• Tokyo Metro Namboku Line, a subway service operated by the Tokyo Metro, labeled
• Nagahori Tsurumi-ryokuchi Line, a subway service operated by the Osaka Metro, labeled
• Transilien Line N, a line of the Paris transport network
• , the official West Japan Railway Company service symbol for the Akō Line.

Engineering

• N, in geotechnical engineering, the result of a standard penetration test
• N, in electrical systems, the 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), a 2008 short story by Stephen King
• Near (Death Note) (alias N), a character in the manga series Death Note
• 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 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), 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

• n, the International Phonetic Alphabet symbol for a voiced alveolar nasal sound
  • n̪, n̼, n̥, ɳ, ɳ̊, ɲ, ɲ̊, ŋ, ŋ̊, ɴ, symbols representing other nasal consonants in the International Phonetic Alphabet
• N (kana), a Japanese kana
• Noun, a part of speech

Other uses

• Hyundai N, high performance brand of Hyundai Motor Company
• 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-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
• November, the military time zone code for UTC−01:00
• Nachrichten-Abteilung, naval intelligence department of Imperial German