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 $n$ , denoted by $P_{n}$
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 $\mathbb {P} _{n}$
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