pi

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The 16th letter of the Greek alphabet. See Table at alphabet.
2. n. Mathematics A transcendental number, approximately 3.14159, represented by the symbol π, that expresses the ratio of the circumference to the diameter of a circle and appears as a constant in many mathematical expressions.
3. n. An amount of type that has been jumbled or thrown together at random.
4. v. To jumble or mix up (type).
5. v. To become jumbled.

Century Dictionary and Cyclopedia

1. n. Printing-types mixed together indiscriminately; type in a confused or jumbled condition or mass.
2. To reduce (printing-types) to a state of pi.
3. n. The name of the Greek letter Π, π, corresponding to the Roman P, p.
4. n. The name of a symbol (π) used in geometry for the ratio of the circumference of a circle to its diameter. or 3.1415927: first so used by Euler.

Wiktionary

1. n. The name of the sixteenth letter of the Classical and Modern Greek alphabets and the seventeenth in Old Greek.
2. n. An irrational and transcendental constant representing the ratio of the circumference of a Euclidean circle to its diameter; approximately 3.1415926535897932384626433832795; usually written π.
3. n. Metal type that has been spilled, mixed together, or disordered. Also called pie.
4. v. To spill or mix printing type. Also, "to pie".
5. adj. Not part of the usual font character set; especially, non-Roman type or symbols as opposed to standard alphanumeric Roman type.
6. abbr. pica (conventionally, 12 points = 1 pica, 6 picas = 1 inch)
7. abbr. piaster

GNU Webster's 1913

1. n. The inorganic orthophoshate ion; -- a symbol used in biochemistry.
2. n. A mass of type confusedly mixed or unsorted.
3. n. A Greek letter (Π, π) corresponding to the Roman letter p.
4. n. The letter π, Π, as used to denote the number or quotient approximately expressing the ratio of the circumference of a circle to its diameter; also, the quotient or the ratio itself. The value of the quotient pi, to twenty decimal places, is 3.14159265358979323846 (see note). The number pi is an irrational number, i.e. it cannot be expressed as the quotient of two integers. It is also a transcendental number, i.e. it cannot be expressed as a root of an algebraic equation with a finite number of terms; and from this fact follows the impossibility of the quadrature of the circle by purely algebraic processes, or by the aid of a ruler and compass.
5. v. To put into a mixed and disordered condition, as type; to mix and disarrange the type of.

WordNet 3.0

1. n. the ratio of the circumference to the diameter of a circle; approximately equal to 3.14159265358979323846...
2. n. the 16th letter of the Greek alphabet
3. n. someone who can be employed as a detective to collect information
4. n. an antiviral drug used against HIV; interrupts HIV replication by binding and blocking HIV protease; often used in combination with other drugs
5. n. the scientist in charge of an experiment or research project