1. a type of shellfish with two rough, flat shells that lives in the ocean and is often eaten as food
2. something that is or can be readily taken advantage of
Usage: idiomatic; usually in the phrase ‘the world is your oyster’

Examples

• We ordered a dozen fresh oysters at the seafood restaurant.
• The oyster shells were sharp and difficult to open.
• She learned to shuck oysters during her summer job.
• Oysters are filter feeders that help clean ocean water.
• The world is your oyster when you have a good education.
• Pearl divers searched for oysters containing valuable gems.