The term is often used interchangeably with punch card, the difference being that an unused card is a "punch card," but once information had been encoded by punching holes in the card, it was now a "punched card."
The term "punch card" and "punched card" are frequently used synonymously. However, there's a subtle difference: a card without holes is called a "punch card," whereas a card that has been punched with information is referred to as a "punched card."