oyster

noun

oys·​ter ˈȯi-stər 

often attributive

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

Examples of oyster in a Sentence

Recent Examples on the Web

Blue crabs and crawfish are sourced from Louisiana, while shellfish such as oysters, Manila clams and cherrystone clams arrive from waters stretching from the East Coast to Asia. — Sara Rosenthal, Denver Post, 11 Oct. 2026

Shipping tags held for oysters were also missing the required documentation. — Joseph Hernandez, Kansas City Star, 10 Oct. 2026

Inside the restaurant, guests chatted among Dean’s signature Guinness-and-oyster shooters and silver bowls piled high with chips, but the warm fall night meant taking advantage of the sidewalk space also appealed. — Leigh Nordstrom, Footwear News, 9 Oct. 2026

Harvesting bivalves, like clams, oysters, scallops and mussels, is especially sustainable because these species do not require feed. — Ian Urbina, Los Angeles Times, 9 Oct. 2026

Word History

Etymology

Middle English oistre, borrowed from Anglo-French oistre, ostre, going back to Latin ostrea, ostreum "bivalve mollusk, oyster," borrowed from Greek óstreion, óstreon, of uncertain origin

Note: Greek óstreion has traditionally been taken to be a derivative, with a suffix -ei-, of a stem going back to Indo-European *h₃esth₁-r-, from the base *h₃esth₁- "bone." See note at ostracon.

First Known Use

13th century, in the meaning defined at sense 1a

Phrases Containing oyster

• European flat oyster
• European oyster
• Olympia oyster
• oyster bed
• oyster crab
• oyster cracker
• oyster drill
• oyster mushroom
• oyster plant
• seed oyster
• the world is someone's oyster
• vegetable oyster

Rhymes for oyster

• cloister
• moister
• royster

Kids Definition

oyster

noun

oys·​ter ˈȯi-stər 

: any of various marine mollusks that include important edible shellfish and have a rough uneven shell made up of two hinged parts and closed by a single muscle