P - Definition and Overview

P is the 16th letter of the Latin alphabet.

Semitic Pê (mouth) as well as Greek Π or π (Pi) and the Etruscan and Latin letters that developed from the former alphabet all symbolized /p/, a plosive, unvoiced consonant. Those who speak Arabic usually have difficulty pronouncing this sound; they pronounce like b instead.

Papa represents the letter P in the NATO phonetic alphabet.

Phonetic use

In English and most other European languages, P is a voiceless bilabial plosive ('p' in the IPA). A common digraph in English is "ph", which represents the voiceless labiodental fricative 'f', and is commonly used to transliterate φ in loanwords from Greek. Both initial and final P can be combined with many other discrete consonants in English words. A common example of assimilation is the tendency of prefixes ending in N to become M before P (such as "in" + "pulse" -> "impulse").

In German, the digraph "pf" is common, representing a labial affricate of 'p' and 'f'.

Meanings for P

• In baseball, P is the abbreviation for the position of pitcher.
• In biochemistry, P is the symbol for proline.
• In chemistry, P is the symbol for the element phosphorus, or sometimes for phosphate.
• In chess, P is sometimes used as a notation symbol for the pawn piece
• In computer science,
  • P is an operation on a semaphore, used for process synchronisation.
  • In complexity theory, P is the set of decision problems solvable in polynomial time on a deterministic Turing machine; see complexity classes P and NP.
• In computing, <p> is the HTML tag to mark the beginning of paragraphs.
• In driving a motor vehicle, P designates the parking gear of an automatic transmission.
• In international licence plate codes, P stands for Portugal.
• In mathematics, blackboard bold <math>\mathbb{P}<math> represents the prime numbers
• In New Zealand P is slang for pure methamphetamine.
• In the Metric system,
  • p, Pico, is an SI prefix meaning 10^-12.
  • P, Peta, is an SI prefix meaning 10¹⁵
  • p is the symbol for the pond, a now obsolete unit of force; see kilopond.
• In British coinage, it is the symbol for penny (pl. pence). i.e. 25p (25 pence).
• In physics,
  • p is the symbol for momentum or pressure
  • P is the symbol power or polarisation;
  • In particle physics, p is the symbol for the proton.
• As the first letter of a postal code,
  • In Canada, P stands for Northern Ontario.
• In probability and statistics,
  • p denotes probability
  • the p-value of a given result in an experiment the is result's significance; that is, the probability of observing this result or a more extreme result, by chance alone.
• In publishing, a circled P, Ⓟ, represents a copyright on a sound recording.
• In symbolic logic, p is often used to denote a proposition as well as q and r.

Two-letter combinations starting with P:

• pa pb pc pd pe pf pg ph pi pj pk pl pm pn po pp pq pr ps pt pu pv pw px py pz

Letter-digit combinations starting with P:

• P0 P1 P2 P3 P4 P5 P6 P7 P8 P9