What does expired card mean?

An expired credit card supposes the card is no more valid, it cannot be longer used. Basically, thee are two reasons why a card becomes expired: it either expires because the term for its validity has passed (5 years, 10 years, depending from one issuer to the other), or if you managed to build yourself a bad credit scoring by being late with your loan payments for example, the card becomes cancelled/freezes, that is you can no longer use it.