Oyster

имя существительное 1) устрица 2) молчун, замкнутый человек 3) серовато-белый цвет Например: close / dumb as an oyster — нем как рыба as like as an apple to an oyster — совершенно непожожие The world is your oyster. — Всё в твоих руках. / Ты - хозяин собственной судьбы.

Большой англо-русский словарь

Oyster

noun Usage: often attributive Etymology: Middle English oistre, from Anglo-French, from Latin ostrea, from Greek ostreon; akin to Greek ostrakon shell, osteon bone — more at osseous 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 Example: 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

Merriam-Webster's Collegiate Dictionary