Definition of pi
plural pis play \ˈpīz\
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
Origin of pi
Middle Greek, from Greek pei, of Semitic origin; akin to Hebrew pē pe
First Known Use: 1638
pi
Definition of pi
plural pies
1 : type that is spilled or mixed
2 : a pi character or matrix
Variants of pi
Origin of pi
origin unknown
First Known Use: circa 1659
pi
Definition of pi
piedpi·ing or pie·ing
transitive verb
: to spill or throw (type or type matter) into disorder
intransitive verb
: to become pied
1889
First Known Use of pi
1889
Variants of pi
pi
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
Variants of pi
PI
Definition of PI
1 Philippine Islands
2 private investigator
3 programmed instruction
See PI defined for Englishlanguage learners
PI Defined for Kids
pi
playDefinition of pi
plural 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
Learn More about pi

Spanish Central: Translation of "pi" Nglish: Translation of "pi" for Spanish speakers Britannica.com: Encyclopedia article about "pi"
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