Cross section (geometry)
PN may refer to:
- p-n junction, a type of junction in electronics
- Pitcairn Islands, ISO 3166-1 country code
- .pn, the country code top level domain (ccTLD) for Pitcairn Islands
- Pacific National, a rail freight company in Australia
- Palmerston North, a city in New Zealand
- Parenteral nutrition
- Part number
- Participatory notes
- Pascal Nouma, a former player of Beşiktaş J.K.
- Pat Nixon, a former First Lady of the United States
- Path graph of size , denoted by
- Patriotic Nigras, a powerful griefing group in Second Life
- Pennsylvania Northeastern Railroad, reporting mark
- Petri Net
- Phylogenetic nomenclature, an approach to naming groups of living things
- Polynomial vector spaces, which may be denoted by
- Post-Newtonian expansion, an approximation of General Relativity
- Pottery Neolithic (see Neolithic)
- Programmer's Notepad, a text editor
- Promissory note, a contract where one party makes an unconditional promise in writing to pay a sum of money to another
- Proper noun, a linguistic term for the name of an entity
- Proportional navigation, a concept in missile guidance systems
- Pseudorandom number sequence
- pseudonoise aka pseudorandom noise, a deterministic sequence of pulses used in spread spectrum communication and rangefinding
- Purple Noon, a 1960 film
Political Parties
- National Renaissance Front, Partidul Naţiunii, a political party in Romania
- Partit Nazzjonalista, a political party in Malta