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

Foods like beef liver and oysters provide well over your daily copper needs in one serving, while oysters, cashews, tofu, and more can offer a substantial portion of this mineral. —Zia Sherrell, Health, 5 Feb. 2026

As one of the largest countries in the world by size, Australia offers something for everyone from incredible sunshine and a sub-tropical climate on Queensland's Gold Coast to wineries and oyster farms in Tasmania, incredible culture in Sydney, and more. —Michael Cappetta, Travel + Leisure, 5 Feb. 2026

Opening dishes will include options such as radicchio agro dolce with goat cheese; sausages and oysters; half of a hen with pan con tomate; and Carnaroli rice pudding with kumquat marmalade. —Stephanie Breijo, Los Angeles Times, 4 Feb. 2026

Dining at the resort is also offering Valentine's Day specific menus featuring bone marrow tartare, pink lady oysters and more; and the spa is offering specials for manicures and pedicures, facials or massages. —Sarah Moore, Freep.com, 3 Feb. 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