Pearl oyster Meaning, Definition & Usage

  1. noun tropical marine bivalve found chiefly off eastern Asia and Pacific coast of North America and Central America; a major source of pearls
    Pinctada margaritifera.

WordNet

Definitions
  1. (Zoöl.), any one of several species of large tropical marine bivalve mollusks of the genus Meleagrina, or Margaritifera, found in the East Indies (especially at Ceylon), in the Persian Gulf, on the coast of Australia, and on the Pacific coast of America. Called also pearl shell, and pearl mussel.
Definitions
  1. . (Zoöl.) See under Pearl.

Webster 1913