A king, queen, or jack/knave card in a standard deck of playing cards.
A postcard measuring approximately 4·75″ × 3·5″, in use mainly in the United Kingdom circa 1894–1902.
A card used to aid rote memorization. One side of the card contains data of one kind, or a question, and the other side contains the associated response which one wants to memorize. For example, one side could contain an English word, and the other side the Spanish translation.
A solid-state digital memory storage format, commonly found on computers, digital cameras and cellphones.