# P

**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.

## 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.
- <P> is the HTML tag for paragraphs.

- Amongst drug users P is slang for pure methamphetamine.
- In international licence plate codes, P stands for Portugal.
- In mathematics, blackboard bold represents the prime numbers
- In the Metric system,
- 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.

- 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*.