pi

noun

1. (countable, uncountable)The sixteenth letter of the Classical and Modern Greek alphabets and the seventeenth in Old Greek.
2. (countable, uncountable)An irrational and transcendental constant representing the ratio of the circumference of a Euclidean circle to its diameter; approximately 3.14159265.
3. (countable, uncountable)Metal type that has been spilled, mixed together, or disordered.
4. pica (conventionally, 12 points = 1 pica, 6 picas = 1 inch).
5. Piaster.
6. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of processing instruction.
7. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of partial induction (see AI).
8. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of personal injury.
9. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of principal investigator (“lead researcher on a grant-funded project”).
10. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of private investigator.
11. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of parallel import.
12. (abbreviation, alt-of, countable, uncountable)Abbreviation of phosphatidylinositol, a phospholipid component of eukaryotic cell membranes, also abbreviated in PtdIns.
13. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of protease inhibitor.
14. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of polyimide.
15. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of ponderal index.
16. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of penile inversion.
17. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of power integrity.
18. (abbreviation, alt-of, countable, uncountable)Abbreviation of prohibited immigrant.
19. (abbreviation, alt-of, countable, initialism, slang, uncountable)Initialism of pseudoincest.
20. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of port injection (“fuel injection”).
21. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of paradoxical intention.
22. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of pro forma invoice.
23. (Philippines, abbreviation, alt-of, countable, initialism, uncountable)Initialism of people's initiative.
24. (abbreviation, alt-of, countable, initialism, uncountable)Initialism of preliminary injunction.

verb

1. To spill or mix printing type.

adj

1. (not-comparable)Not part of the usual font character set; especially, non-Roman type or symbols as opposed to standard alphanumeric Roman type.

   “In computing, pi characters may be entered with special key combinations.”

2. Pious.

   “Our Major was "Cherub" Cheeseman, noted for his foul language. I am afraid he lost a tidy little legacy that he was expecting from his aunt, the Dowager Lady Shuttlecock (a very "pi" old lady), through this same habit of his.”

   ““Those are very 'pi' sentiments. Was a preacher in Staffordshire— I was raised chapel, though've tried to forget it—he talked that way... redemption and the lot.””

   “In Sense and Sensibility, as even you might agree, there's at least the danger of a rather pi moral framework clamping down on the spontaneous fun and leaving the sisters to survive - a bit drearily - on the periphery of a mean world.”

3. (abbreviation, alt-of, initialism)Initialism of politically incorrect (see PC).

name

1. (abbreviation, alt-of)Abbreviation of Piauí: a state of Brazil.
2. (abbreviation, alt-of, initialism)Initialism of Prison Industries, the prison-run work program for inmates.
3. (Philippines, US, abbreviation, alt-of, dated, historical, initialism)Initialism of Philippine Islands.

   “We're going back to the PI for a vacation this summer.”

4. (historical)A county of Chengdu, Sichuan, China.

   “Pi County has brought democracy into full play. The peasants there are electing production team leaders and other production team cadres by secret ballot.”

   “[...]water carriers, the sedanchair carriers, the pawn brokers, and even the manure collectors in a market town in Pi county, Szechwan in the late Ch'ing period.”

   “In addition to my own residential complex, I also engaged in ethnographic observation and conducted interviews with Party cadres and local residents in four similar apartment complexes in Dujiangyan and two in neighboring Pi County.”