|a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.|
|a gadget; dingus; thingumbob.|
|—n , pl pis|
|1.||the 16th letter in the Greek alphabet (Π, π), a consonant, transliterated as p|
|2.||maths a transcendental number, fundamental to mathematics, that is the ratio of the circumference of a circle to its diameter. Approximate value: 3.141 592…; symbol: π|
|[C18 (mathematical use): representing the first letter of Greek periphereia|
n. pl. pis
Symbol π The 16th letter of the greek alphabet.
The pH value for the isoelectric point of a given substance in solution.
|pi (pī) Pronunciation Key
An irrational number that has a numerical value of 3.14159265358979... and is represented by the symbol π. It expresses the ratio of the circumference to the diameter of a circle and appears in many mathematical expressions.