pi

¹

[ pahy ]

noun

, plural pis.

1. the 16th letter of the Greek alphabet (Π, π).
2. the consonant sound represented by this letter.
3. Mathematics.
   1. the letter π, used as the symbol for the ratio of the circumference of a circle to its diameter.
   2. the ratio itself: 3.141592+.

pi

²

or pie

[ pahy ]

noun

, plural pies.

1. printing types mixed together indiscriminately.
2. any confused mixture; jumble.

verb (used with object)

, pied, pi·ing.

1. to reduce (printing types) to a state of confusion.
2. to jumble.

PI

³

1. Law. personal injury.
2. principal investigator.
3. Also P.I., p.i. private investigator.

Pi.

⁴

or pi.

abbreviation for

1. piaster.

P.I.

⁵

abbreviation for

1. Philippine Islands.
2. Also PI, p.i. private investigator.

pi

¹

/ paɪ /

adjective

1. See pious
   slang.
   short for pious pious

pi

²

/ paɪ /

noun

1. a jumbled pile of printer's type
2. a jumbled mixture

verb

1. to spill and mix (set type) indiscriminately
2. to mix up

pi

³

/ paɪ /

noun

1. the 16th letter in the Greek alphabet (Π, π), a consonant, transliterated as p
2. maths a transcendental number, fundamental to mathematics, that is the ratio of the circumference of a circle to its diameter. Approximate value: 3.141 592…; symbol: π

PI

⁴

abbreviation for

1. Philippine Islands
2. private investigator

pi

/ pī /

1. An irrational number that has a numerical value of 3.14159265358979… and is represented by the symbol π. It expresses the ratio of the circumference to the diameter of a circle and appears in many mathematical expressions.

pi

1. The irrational number obtained by dividing the length of the diameter of a circle into its circumference . Pi is approximately 3.1416. The sign for pi is π.

Word History and Origins

Origin of pi¹

First recorded in 1835–45; from Greek pî, peî, used in mathematics to represent Greek periphérion periphery ( def )

Origin of pi²

First recorded in 1650–60; origin uncertain

Word History and Origins

Origin of pi¹

C17: of uncertain origin

Origin of pi²

C18 (mathematical use): representing the first letter of Greek periphereia periphery

Example Sentences

Both PIs doubt unstable Tabor’s guilt, and as they explore his case, they mix it up with some of the more ice-in-their-veins denizens of the New York art scene.

From Washington Post

In the end, they had PIs calculate the maximum number of researchers who could be in their lab at once, given the 160-square-feet rule, and divvy up the available hours as they saw fit.

From MIT Technology Review

In Pi, a numbers theorist named Max Cohen decides to put a power drill through his own brain.

From The Daily Beast

They included Yann Martel, author of Life of Pi, and Calvin Trillin.

From The Daily Beast

Life of Pi immediately became the odds-on favorite to win, with more bets placed on it than any other Booker nominee ever.

From The Daily Beast

She was Richard Parker in Life of Pi, a tiger who confusingly talked, and with an Indian accent, to boot.

From The Daily Beast

PE, like fe, is another Hebrew letter, tho Greek and math people prefer their PI better.

From The Daily Beast

"Quelle parole pi paura d' inganno che speranza di futuro frutto mi porsero," he tells us in the Filocolo, ed.

From Project Gutenberg

And then Pi′tamakan went in and cut the ropes of eight horses, and safely led them out, making in all fifteen that she had taken.

From Project Gutenberg

And so passed Pi′tamakan, virgin, and brave woman chief of our people.

From Project Gutenberg

The Blackfeet call such a place—there were several of them—a pi′skan, a trap.

From Project Gutenberg

Pi′tamakan then ordered her followers to remain where they were and told the Blood chief to say the same thing to his men.

From Project Gutenberg

Related Words

• inquiry agent
• P.I.
• private detective
• private dick
• private eye
• private investigator
• sleuth