pi

1 of 5

noun (1)

plural pis ˈpīz How to pronounce pi (audio)
1
: the 16th letter of the Greek alphabet see Alphabet Table
2
a
: the symbol π denoting the ratio of the circumference of a circle to its diameter
b
: the ratio itself : a transcendental number having a value rounded to eight decimal places of 3.14159265

pi

2 of 5

noun (2)

variants or less commonly pie
plural pies
1
: type that is spilled or mixed
2
: a pi character or matrix

pi

3 of 5

verb

variants or less commonly pie
pied; piing or pieing

transitive verb

: to spill or throw (type or type matter) into disorder

intransitive verb

: to become pied

pi

4 of 5

adjective

variants or less commonly pie
1
: not intended to appear in final printing
pi lines
2
: capable of being inserted only by hand
pi characters

PI

5 of 5

abbreviation

1
Philippine Islands
2
private investigator
3
programmed instruction

Examples of pi in a Sentence

Recent Examples on the Web
Noun
Every March 14, the university releases its decision letters to prospective students at 6:28 p.m. Eastern to honor tau, which is double the value of pi. Defne Karabatur, Los Angeles Times, 14 Mar. 2024 The first calculation of pi was done by Archimedes, a legendary mathematician of the ancient world, in the centuries leading up to the common era. Emily Mae Czachor, CBS News, 14 Mar. 2024 Tuesday’s first event, from 11 a.m. to 3 p.m., will feature lots of numerical fun, a pi parade and wrap up with the eating of pie. Linda Zavoral, The Mercury News, 13 Mar. 2024 According to the Guinness World Records, the most accurate value of pi is 62,831,853,071,796 digits, achieved by the University of Applied Sciences of the Grisons in Switzerland in August 2021. Grace Tucker, The Enquirer, 13 Mar. 2024 For comparison, in 2022 the record number of calculated digits of pi was 62x1012. Manon Bischoff, Scientific American, 24 Jan. 2024 The nickname is based on the Greek letter that represents the number value of pi twice, which is about 6.28, which is the date of Musk’s birthday on June 28. David Chiu, Peoplemag, 12 Sep. 2023 Pumpkin pi Who helped the mini pumpkin cross the road? Briannah Rivera, Seventeen, 6 July 2023 Pi Day is a celebration of pi, the mathematical constant that starts 3.14, which also can be read as March 14. Deborah Martin, San Antonio Express-News, 14 Mar. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'pi.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

Noun (1)

Middle Greek, from Greek pei, of Semitic origin; akin to Hebrew pe

Noun (2)

origin unknown

First Known Use

Noun (1)

15th century, in the meaning defined at sense 1

Noun (2)

circa 1659, in the meaning defined at sense 1

Verb

1889, in the meaning defined at transitive sense

Adjective

circa 1940, in the meaning defined at sense 1

Time Traveler
The first known use of pi was in the 15th century

Dictionary Entries Near pi

Cite this Entry

“Pi.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/pi. Accessed 28 Mar. 2024.

Kids Definition

pi

noun
ˈpī
plural pis
ˈpīz
1
: the 16th letter of the Greek alphabet
Π or π
2
a
: the symbol π representing the ratio of the circumference of a circle to its diameter
b
: the ratio itself having a value of approximately 3.1416

Legal Definition

P&I

1 of 2 abbreviation
principal and interest

PI

2 of 2 abbreviation
private investigator

More from Merriam-Webster on pi

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