pi (pì) noun
plural pis
1. The 16th letter of the Greek alphabet.
2. Mathematics. A transcendental number, approximately 3.14159, represented by the symbol p, that expresses the ratio of the circumference to the diameter of a circle and appears as a constant in many mathematical expressions.
[Medieval Greek, from Greek pei, of Phoenician origin; akin to Hebrew pê.]

verb
pied (pìd) also pied piing pieing pies pies verb, transitive
To jumble or mix up (type).