资料来源 : Webster's Revised Unabridged Dictionary (1913)

Oyster \Oys"ter\, n. [OF. oistre, F. hu[^i]tre, L. ostrea,
   ostreum, Gr. 'o`streon; prob. akin to 'ostre`on bone, the
   oyster being so named from its shell. Cf. {Osseous},
   {Ostracize}.]
   1. (Zo["o]l.) Any marine bivalve mollusk of the genus Ostrea.
      They are usually found adhering to rocks or other fixed
      objects in shallow water along the seacoasts, or in
      brackish water in the mouth of rivers. The common European
      oyster ({Ostrea edulis}), and the American oyster ({Ostrea
      Virginiana}), are the most important species.

   2. A name popularly given to the delicate morsel contained in
      a small cavity of the bone on each side of the lower part
      of the back of a fowl.

   {Fresh-water oyster} (Zo["o]l.), any species of the genus
      {Etheria}, and allied genera, found in rivers of Africa
      and South America. They are irregular in form, and attach
      themselves to rocks like oysters, but they have a pearly
      interior, and are allied to the fresh-water mussels.

   {Oyster bed}, a breeding place for oysters; a place in a
      tidal river or other water on or near the seashore, where
      oysters are deposited to grow and fatten for market. See
      1st {Scalp}, n.

   {Oyster catcher} (Zo["o]l.), any one of several species of
      wading birds of the genus {H[ae]matopus}, which frequent
      seashores and feed upon shellfish. The European species
      ({H. ostralegus}), the common American species ({H.
      palliatus}), and the California, or black, oyster catcher
      ({H. Bachmani}) are the best known.

   {Oyster crab} (Zo["o]l.) a small crab ({Pinnotheres ostreum})
      which lives as a commensal in the gill cavity of the
      oyster.

   {Oyster dredge}, a rake or small dragnet of bringing up
      oyster from the bottom of the sea.

   {Oyster fish}. ({Zo["o]l}.)
      (a) The tautog.
      (b) The toadfish.

   {Oyster plant}. (Bot.)
      (a) A plant of the genus {Tragopogon} ({T. porrifolius}),
          the root of which, when cooked, somewhat resembles the
          oyster in taste; salsify; -- called also {vegetable
          oyster}.
      (b) A plant found on the seacoast of Northern Europe,
          America and Asia ({Mertensia maritima}), the fresh
          leaves of which have a strong flavor of oysters.

   {Oyster plover}. (Zo["o]l.) Same as {Oyster catcher}, above.
      

   {Oyster shell} (Zo["o]l.), the shell of an oyster.

   {Oyster wench}, {Oyster wife}, {Oyster women}, a women who
      deals in oysters.

   {Pearl oyster}. (Zo["o]l.) See under {Pearl}.

   {Thorny oyster} (Zo["o]l.), any spiny marine shell of the
      genus {Spondylus}.

Pearl \Pearl\, n. [OE. perle, F. perle, LL. perla, perula,
   probably fr. (assumed) L. pirulo, dim. of L. pirum a pear.
   See {Pear}, and cf. {Purl} to mantle.]
   1. (Zo["o]l.) A shelly concretion, usually rounded, and
      having a brilliant luster, with varying tints, found in
      the mantle, or between the mantle and shell, of certain
      bivalve mollusks, especially in the pearl oysters and
      river mussels, and sometimes in certain univalves. It is
      usually due to a secretion of shelly substance around some
      irritating foreign particle. Its substance is the same as
      nacre, or mother-of-pearl. Pearls which are round, or
      nearly round, and of fine luster, are highly esteemed as
      jewels, and compare in value with the precious stones.

   2. Hence, figuratively, something resembling a pearl;
      something very precious.

            I see thee compassed with thy kingdom's pearl.
                                                  --Shak.

            And those pearls of dew she wears.    --Milton.

   3. Nacre, or mother-of-pearl.

   4. (Zo["o]l.) A fish allied to the turbot; the brill.

   5. (Zo["o]l.) A light-colored tern.

   6. (Zo["o]l.) One of the circle of tubercles which form the
      bur on a deer's antler.

   7. A whitish speck or film on the eye. [Obs.] --Milton.

   8. A capsule of gelatin or similar substance containing some
      liquid for medicinal application, as ether.

   9. (Print.) A size of type, between agate and diamond. [hand]
      This line is printed in the type called pearl.

   {Ground pearl}. (Zo["o]l.) See under {Ground}.

   {Pearl barley}, kernels of barley, ground so as to form
      small, round grains.

   {Pearl diver}, one who dives for pearl oysters.

   {Pearl edge}, an edge of small loops on the side of some
      kinds of ribbon; also, a narrow kind of thread edging to
      be sewed on lace.

   {Pearl eye}, cataract. [R.]

   {Pearl gray}, a very pale and delicate blue-gray color.

   {Pearl millet}, Egyptian millet ({Penicillaria spicata}).

   {Pearl moss}. See {Carrageen}.

   {Pearl moth} (Zo["o]l.), any moth of the genus {Margaritia};
      -- so called on account of its pearly color.

   {Pearl oyster} (Zo["o]l.), 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}.

   {Pearl powder}. See {Pearl white}, below.

   {Pearl sago}, sago in the form of small pearly grains.

   {Pearl sinter} (Min.), fiorite.

   {Pearl spar} (Min.), a crystallized variety of dolomite,
      having a pearly luster.

   {Pearl white}.
      (a) Basic bismuth nitrate, or bismuth subchloride; -- used
          chiefly as a cosmetic.
      (b) A variety of white lead blued with indigo or Berlin
          blue.

资料来源 : WordNet®

pearl oyster
     n : tropical marine bivalve found chiefly off eastern Asia and
         Pacific coast of North America and Central America; a
         major source of pearls [syn: {Pinctada margaritifera}]