The crossword solution for the term 'WHAT'S IN A _____?' is NAME, with four letters. This phrase is a play on the famous line from Romeo and Juliet by William Shakespeare, 'What's in a NAME? That which we call a rose by any other NAME would smell as sweet.' The phrase is used to emphasize that a NAME does not define a person or thing, and that what matters most is the essence of the person or thing, not its NAME.