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

If slurping the bivalves at restaurants isn’t enough, there are oodles of festivals celebrating the Lowcountry staple throughout the winter, including the Lowcountry Oyster Festival, the world’s largest oyster festival, which takes place on February 1, 2026. —Mark Ellwood, AFAR Media, 7 Nov. 2025

Guy recommends mixed gourmet mushrooms such as shiitakes, creminis, and oyster. —Heather Riske, Better Homes & Gardens, 6 Nov. 2025

The menu here includes a raw bar filled with oysters, seafood cocktail with tomato avocado, Bangs Island mussels with green curry, and tuna crudo, as well as hors d’oeuvres like steak tartare and frog legs Kiev. —Nicole Hoey, Robb Report, 5 Nov. 2025

As a successful oyster-gathering and farming village, farmers harvested blueberries, sweet potatoes, asparagus and, most importantly, strawberries. —Mackenzie Cummings-Grady, Billboard, 5 Nov. 2025

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