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

A couple dozen Kumamoto oysters, 20% off, and shipped fresh by the reputable folks at Fulton Street Fish Market (don’t mess around with sketchy online seafood delivery) will bring their subtle creaminess to my festivities this winter. —Wilder Davies, Bon Appetit Magazine, 1 Dec. 2025

Akihiro Takeuchi lost 80% of his juvenile oysters to a mysterious illness six years ago. —Arkansas Online, 1 Dec. 2025

The world is truly your winter manicure oyster. —Kiana Murden, Vogue, 30 Nov. 2025

Floripa is the oyster capital of Brazil—and Rancho Açoriano in Ribeirão da Ilha is one of the most classic seafood restaurants to try them, freshly harvested from nearby farms. —Carla Vianna, Travel + Leisure, 29 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