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

Other foodborne illnesses related to oysters Oysters are also frequently tied to outbreaks of salmonella and norovirus. —Eva Flowe june 11, Charlotte Observer, 11 June 2026

Adios to dollar oyster nights and stone crabs in season. —Connie Ogle june 11, Miami Herald, 11 June 2026

With 48% of votes counted, Platner, an oyster farmer and former Marine, was winning with 72% to 20% for Mills. —Phillip M. Bailey, USA Today, 10 June 2026

Maine Democrats on Tuesday nominated their own version of Walker in Graham Platner, an oyster farmer with a thick and messy oppo file that includes Nazi imagery, sexting with women other than his wife, and allegations of domestic abuse. —Philip Elliott, Time, 10 June 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