\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}.