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

Highlights of the space are a six-foot oyster artwork made with shells from Louisiana and an oak desk with a large slab of Alabama white marble. —Jean E. Palmieri, Footwear News, 3 Nov. 2025

Though unsafe to eat from city waters, oysters are among the most efficient purifying devices, each adult capable of filtering up to fifty gallons a day. —Ben McGrath, New Yorker, 3 Nov. 2025

Appetizers include oysters, salmon or scallop crudo, and tuna tartare with Fresno chiles. —Bud Kennedy, Fort Worth Star-Telegram, 3 Nov. 2025

Modern scalloped oysters likely have roots in oyster pie, a traditional Virginia dish that dates back to the 1700s, according to Bernie Herman, a renowned folklorist and professor of Southern studies at UNC Chapel Hill. —Mary Shannon Wells, Southern Living, 2 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