The term 'JACK OR ACE' can be solved by the four-letter word 'CARD'. A CARD is a thin, flat piece of paper or thin cardboard, typically rectangular and used for various purposes such as playing games, writing messages, or for educational purposes. Cards are usually made of paper or plastic and are often decorated with pictures or designs. The two terms 'JACK' and 'ACE' refer to specific cards in a deck of playing cards. A JACK is a face CARD that usually has a picture of a man on it, while an ACE is the highest-ranking CARD in a deck.