The crossword solution for the term 'Call a spade a heart?' is 'MISNAME'. This is an idiom which means to refer to something by a wrong name. It is often used to describe someone who is deliberately trying to deceive or mislead others by using a false name. The phrase is derived from the game of cards, where a spade is a suit and a heart is another suit. By calling a spade a heart, one is attempting to disguise the true nature of the card.