pi Meaning, Definition & Usage

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

WordNet

Pi noun
Etymology
See Pica, Pie magpie, service-book.
Definitions
  1. (Print.) A mass of type confusedly mixed or unsorted. Written also pie. math. the ratio of the circumference to the diameter of a circle
Pi transitive verb
Wordforms
imperfect & past participle Pied ; present participle & verbal noun Pieing
Definitions
  1. (Print.) To put into a mixed and disordered condition, as type; to mix and disarrange the type of; as, to pi a form. Written also pie.

Webster 1913