Definition of pi
pis
play \ˈpīz\1 : the 16th letter of the Greek alphabet — see alphabet table
2a : the symbol π denoting the ratio of the circumference of a circle to its diameterb : the ratio itself : a transcendental number having a value rounded to eight decimal places of 3.14159265
Origin and Etymology of pi
Middle Greek, from Greek pei, of Semitic origin; akin to Hebrew pē pe
First Known Use: 15th century
pi
Definition of pi
pies
1 : type that is spilled or mixed
2 : a pi character or matrix
Origin and Etymology of pi
origin unknown
First Known Use: circa 1659
pi
pie
Definition of pi
pied
;piing
orpieing
transitive verb
: to spill or throw (type or type matter) into disorder
intransitive verb
: to become pied
1889
First Known Use of pi
1889
pi
pie
Definition of pi
1 : not intended to appear in final printing <pi lines>
2 : capable of being inserted only by hand <pi characters>
Circa 1940
First Known Use of pi
circa 1940
PI
Definition of PI
1 Philippine Islands
2 private investigator
3 programmed instruction
PI Defined for Kids
pi
playDefinition of pi for Students
pis
\ˈpīz\1 : the symbol π representing the ratio of the circumference of a circle to its diameter
2 : the ratio itself having a value of about 3.1416
Law Dictionary
PI
Legal Definition of PI
private investigator
Learn More about pi

See words that rhyme with pi Spanish Central: Translation of pi Nglish: Translation of pi for Spanish speakers Britannica.com: Encyclopedia article about pi
Seen and Heard
What made you want to look up pi? Please tell us where you read or heard it (including the quote, if possible).
Writing? Check your grammar now!