noun

1. The 16th letter of the Classical and Modern Greek alphabets and the seventeenth in Old Greek.

2. An irrational and transcendental constant representing the ratio of the circumference of a Euclidean circle to its diameter; approximately 3.14159265358979323846264338327950; usually written π.

3. Metal type that has been spilled, mixed together, or disordered.

Synonyms: Archimedes' constant, Ludolph's constant, Ludolph's number, Ludolphian number, pie