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

Open only on the weekends from May to October, this has become our apéro (French version of pre-dinner drinks and snacks) ritual, ordering freshly shucked oysters and prawns from the waterfront stand before settling into one of the picnic tables spilling out along the terrace on the quay. —Lane Nieset, Travel + Leisure, 7 Dec. 2025

The priciest item on the menu is a $199 seafood tower with six oysters, seven shrimp, a half-pound of king crab, six crab claws and a whole lobster tail. —Bradley Hohulin, IndyStar, 5 Dec. 2025

For people with higher iron needs, such as those with heavy menstrual cycles or low iron stores, oysters can be a particularly effective option for raising iron levels. —Jillian Kubala, Health, 4 Dec. 2025

For $18, guests can choose from a burger and a beer, ahi tuna tacos and a margarita, raw oysters and a martini, falafel and a gin and tonic, salmon and a glass of white wine or a shrimp roll with a glass of chardonnay. —Carlos Rico, San Diego Union-Tribune, 4 Dec. 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