"I got nothin" is a phrase commonly used to express that one does not have anything to contribute or offer in a particular situation. In a card game context, it is a sad declaration made when a player does not have any cards of value or any viable moves to make.
Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: Sad declaration in a card game. Explanations are generated by AI and may be inaccurate.