oyster

Everyday

1. A sea animal with a soft body inside a rough, hinged shell; some are eaten as food. tree →
2. A pearl oyster: a kind of oyster that can make a pearl inside its shell. tree →
3. In the saying «the world is your oyster»: you can go anywhere and do anything you choose. tree →

In the lessons

In science, oysters are molluscs that filter water to feed; oyster reefs clean the sea. In history and food, oysters were once a cheap food in London. The idiom «the world is your oyster» is often said to young people leaving school. Phrases: «oyster shell», «pearl oyster», «oyster bed», «the world is your oyster».

Examples

• An oyster has a hard rough shell. tree →
• A pearl grows inside an oyster when sand or grit gets in. tree →
• Oysters clean the water by filtering it. tree →
• Grandad loves eating oysters at the seaside. tree →
• You're young and clever — the world is your oyster! tree →
• Fishermen collected oysters from the oyster beds. tree →
• London's «Oyster card» is used to pay for buses and the Tube. tree →
• One day the fisherman went out fishing, and among his catch for the day he brought home three dozen oysters. tree →

Note

Countable: an oyster, oysters (use «an»). Myth: not every oyster makes pearls, and pearls usually form around a tiny parasite or bit of tissue, not just a grain of sand. Safety: raw oysters can make people ill; only eat them fresh from a safe source.