Definitions

from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun The 16th letter of the Greek alphabet.
  • noun Mathematics A transcendental number, approximately 3.14159, represented by the symbol π, that expresses the ratio of the circumference to the diameter of a circle and appears as a constant in many mathematical expressions.
  • noun An amount of type that has been jumbled or thrown together at random.
  • intransitive verb To jumble or mix up (type).
  • intransitive verb To become jumbled.

from The Century Dictionary.

  • noun The name of the Greek letter Π, π, corresponding to the Roman P, p.
  • noun The name of a symbol (π) used in geometry for the ratio of the circumference of a circle to its diameter. or 3.1415927: first so used by Euler.
  • noun Printing-types mixed together indiscriminately; type in a confused or jumbled condition or mass.
  • To reduce (printing-types) to a state of pi.

from the GNU version of the Collaborative International Dictionary of English.

  • transitive verb (Print.) To put into a mixed and disordered condition, as type; to mix and disarrange the type of.
  • noun acronym The inorganic orthophoshate ion; -- a symbol used in biochemistry.
  • noun (Print.) A mass of type confusedly mixed or unsorted.
  • noun A Greek letter (Π, π) corresponding to the Roman letter p.
  • noun (Math.) The letter π, Π, as used to denote the number or quotient approximately expressing the ratio of the circumference of a circle to its diameter; also, the quotient or the ratio itself. The value of the quotient pi, to twenty decimal places, is 3.14159265358979323846 (see note). The number pi is an irrational number, i.e. it cannot be expressed as the quotient of two integers. It is also a transcendental number, i.e. it cannot be expressed as a root of an algebraic equation with a finite number of terms; and from this fact follows the impossibility of the quadrature of the circle by purely algebraic processes, or by the aid of a ruler and compass.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun The name of the sixteenth letter of the Classical and Modern Greek alphabets and the seventeenth in Old Greek.
  • noun mathematics An irrational and transcendental constant representing the ratio of the circumference of a Euclidean circle to its diameter; approximately 3.1415926535897932384626433832795; usually written π.
  • noun Metal type that has been spilled, mixed together, or disordered. Also called pie.
  • verb To spill or mix printing type. Also, "to pie".
  • adjective typography Not part of the usual font character set; especially, non-Roman type or symbols as opposed to standard alphanumeric Roman type.
  • abbreviation typography pica (conventionally, 12 points = 1 pica, 6 picas = 1 inch)
  • abbreviation piaster

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun the ratio of the circumference to the diameter of a circle; approximately equal to 3.14159265358979323846...
  • noun the 16th letter of the Greek alphabet
  • noun someone who can be employed as a detective to collect information
  • noun an antiviral drug used against HIV; interrupts HIV replication by binding and blocking HIV protease; often used in combination with other drugs
  • noun the scientist in charge of an experiment or research project

Etymologies

from The American Heritage® Dictionary of the English Language, 4th Edition

[Late Greek , from Greek pei, of Phoenician origin; see p in Semitic roots.]

from The American Heritage® Dictionary of the English Language, 4th Edition

[Origin unknown.]

Support

Help support Wordnik (and make this page ad-free) by adopting the word pi.

Examples

  • PiBook: NoXIB pi$ find. - type f - print0 | xargs -0 perl - pi - e 's/NoXIB/___PROJECTNAME___/g '

    The Code Project Latest Articles Ohmu 2010

  • PiBook: NoXIB pi$ find. - type f - print0 | xargs -0 perl - pi - e 's/NoXIB/___PROJECTNAME___/g '

    The Code Project Latest Articles 2010

  • ; MMHK_CurrentVector - > The direction of the current mouse movement in radians. (a float between - pi & +pi. 0 is left, - pi & +pi is right) #Persistent return

    AutoHotkey Community 2008

  • ; MMHK_CurrentVector - > The direction of the current mouse movement in radians. (a float between - pi & +pi. 0 is left, - pi & +pi is right) #Persistent return

    AutoHotkey Community 2008

  • - rw-rw-rw - 1 pi admin 335 27 Aug 15: 50 main. m PiBook: NoXIB pi$ mv NoXIB_Prefix. pch

    The Code Project Latest Articles Ohmu 2010

  • - rw-rw-rw - 1 pi admin 335 27 Aug 15: 50 main. m PiBook: NoXIB pi$ mv NoXIB_Prefix. pch

    The Code Project Latest Articles 2010

  • - > The direction of the current mouse movement in radians. (a float between - pi & +pi.

    AutoHotkey Community 2008

  • - > The direction of the current mouse movement in radians. (a float between - pi & +pi.

    AutoHotkey Community 2008

  • - > The direction of the current mouse movement in radians. (a float between - pi & +pi.

    AutoHotkey Community 2008

  • I have already mentioned that the dwellings of the islanders were almost invariably built upon massive stone foundations, which they call pi-pis.

    Typee Herman Melville 1855

Comments

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  • Beautiful number. Trying to memorize up to Feynman point.

    October 6, 2007

  • So you're a piphilologist, are you?

    October 6, 2007

  • I enjoy how Wikipedia explains the Feynman point joke,

    "The humorous irony of this statement is the suggestion that..."

    Which means that if you've read that far, you're not going to find it funny.

    October 6, 2007

  • Yeah, they kind of kill it right there, don't they?

    October 6, 2007

  • Extrapolating my schooltide mathematics I calculate that I could fill all available space on every server on the world wide web with the number represented by this one Greek letter. Now would that be some Trojan Horse?

    February 17, 2008

  • And then would pi itself be the antidote?

    February 17, 2008

  • Seen here.

    December 24, 2008

  • JM wonders if some folk owe their large circumference to too much pi.

    May 31, 2011

  • WORD: pi (π)

    DEFINITION:

    (1) In the grand tradition of the supermarket tabloid The National Enquirer, pi (π) is the mathematical constant which, to Kurt Vonnegut's way of thinking, exposes the "secret lives" of circles.

    (2) " The number π is a mathematical constant that is the ratio of a circle's circumference to its diameter, and is approximately equal to 3.14159. It has been represented by the Greek letter "π" since the mid-18th century, though it is also sometimes written as "pi" (/paɪ/). π is an irrational number, which means that it cannot be expressed exactly as a ratio of any two integers (fractions such as 22/7 are commonly used to approximate π; no fraction can be its exact value); consequently, its decimal representation never ends and never settles into a permanent repeating pattern. The digits appear to be randomly distributed, although no proof of this has yet been discovered. π is a transcendental number – a number that is not the root of any nonzero polynomial having rational coefficients. The transcendence of π implies that it is impossible to solve the ancient challenge of squaring the circle with a compass and straight-edge." -- Wikipedia

    EXAMPLE:

    ' And now I drew a symbol whose meaning *Dwayne had known for a few years in school, a meaning which had since eluded him. The symbol would have looked like the end of a table in a prison dining hall to *Wayne. It represented the ratio of the circumference of a circle to its diameter. This ratio could also could also be expressed as a number, and even as . . . all the rest of us went about our business, Earthling scientists were monotonously radioing that number into outer space. The idea was to show other inhabited planets, in case they were listening, how intelligent we were. We had tortured circles until they coughed up this symbol of their secret lives:

    ' pi π '

    -- From Kurt Vonnegut's 1973 novel Breakfast of Champions -- Chapter 19 (page 207).

    1973 KURT VONNEGUT, JR. Breakfast of Champions, or, Goodbye Blue Monday.

    * NOTE: "Wayne" is not a typo here. "Dwayne" and "Wayne" are two entirely different characters in Vonnegut's novel. Dwayne, for instance, is white, and Wayne is black.

    August 28, 2013

  • New mnemonic system for pi at: https://www.futilitycloset.com/2018/07/19/piphilology/.

    July 20, 2018

  • "Myturtlepanchowillmylovepickupmynewmovergingermame."


    This is a mnemonic for pi out to 25 decimal places based on a system shown in the book "Mathemagics - How To Look Like a Genius Without Really Trying." 

    All the integers 1 thru 9 occur in the expansion except "0". After "mame" add: "a famous Nike belle" and the next digit (the 32nd) is "0".



    July 20, 2018