A card is typically a rectangular or square piece of thick paper or thin cardboard used for various purposes, such as playing games, identification, or conveying information. In the context of the clue "Jack, but not Jill," it refers to a playing card featuring the rank of Jack.
Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: 9 or 10, but not 11 or 12. Explanations are generated by AI and may be inaccurate.