1. noun /paɪ/
a) The name of the sixteenth letter of the Classical and Modern Greek alphabets and the seventeenth in Old Greek.
b) An irrational and transcendental constant representing the ratio of the circumference of a Euclidean circle to its diameter; approximately 3.1415926535897932384626433832795; usually written π.
Syn: Archimedes constant, Ludolphs constant, Ludolphs number
2. verb /paɪ/
To spill or mix printing type. Also, "to pie".
3. adjective /paɪ/
Not part of the usual font character set; especially, non-Roman type or symbols as opposed to standard alphanumeric Roman type.
In computing, pi characters are entered with special combinations of keys like ctrl-alt-x, or via character sequences such as .
See Also: cicero, pica stick
Wikipedia foundation.