0 the date at which a document, agreement, etc. has no legal force or can no longer be used:
1 the date printed on the container of an item for sale, especially food or medicine, after which the item can no longer be sold and should not be used:
Food product labels must specify weights, ingredients, nutritional content, and expiry date.
Never take any medication that is past its expiry date.
2 the last day on which an option (= the right to buy or sell particular shares) can be used: