noun The sixteenth letter of the Classical and Modern Greek alphabets and the seventeenth in Old Greek.
noun An irrational and transcendental constant representing the ratio of the circumference of a Euclidean circle to its diameter; approximately 3.14159265.
noun Metal type that has been spilled, mixed together, or disordered.
verb To spill or mix printing type.
adjective 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 may be entered with special key combinations.