oyster

noun, often attributive oys·ter \ ˈȯi-stər \

Definition of oyster

1 a :any of various marine bivalve mollusks (family Ostreidae) that have a rough irregular shell closed by a single adductor muscle and include commercially important shellfish
b :any of various mollusks resembling or related to the oysters
2 :something that is or can be readily made to serve one's personal ends
  • the world was her oyster
3 :a small mass of muscle contained in a concavity of the pelvic bone on each side of the back of a fowl
4 :an extremely taciturn person
5 :a grayish-white color

Recent Examples of oyster from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'oyster.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of oyster

Middle English oistre, from Anglo-French, from Latin ostrea, from Greek ostreon; akin to Greek ostrakon shell, osteon bone — more at osseous



OYSTER Defined for English Language Learners

oyster

noun

Definition of oyster for English Language Learners

  • : a type of shellfish that has a rough shell with two parts and that is eaten both cooked and raw


OYSTER Defined for Kids

oyster

noun oys·ter \ ˈȯi-stər \

Definition of oyster for Students

:a shellfish that lives on stony bottoms ( oyster beds ) in shallow seawater, has a rough grayish shell made up of two hinged parts, and is often used for food


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