Pi (pī), n. [Gr. pi^.]
1. A Greek
letter (Π, π) corresponding to the Roman
letter P.
2. Specif.: (Math.) The letter Π, π, as used
to denote the number or
quotient approximately expressing the ratio of
the circumference of a circle to its diameter; also, the quotient or the ratio
itself. The value of the
quotient pi, to eight decimal places, is 3.14159265. The quotient pi cannot be expressed as a
root of an algebraic equation; and from this
fact follows the impossibility of the quadrature of the circle
by purely algebraic processes, or by the aid of a ruler and compass.
Pi , v. t. [imp. & p. p. Pied (?); p. pr. & vb. n. Pieing (?).]
(Print.) To put into a mixed and disordered condition,
as type; to
mix and disarrange the type of; as, to pi a form. [Written also pie.]
Pi (?), n. [See Pica, Pie magpie, service-book.]
(Print.) A mass of type
confusedly mixed or unsorted. [Written also pie.]
Hear it pronounced