The term 'Be a Union Buster' refers to an individual who works to prevent the formation of labor unions. This is usually done by convincing workers not to join a union, or by attempting to break up existing unions. The crossword solution for this term is 'SECEDE, ' which means to withdraw formally from an organization or alliance. This term is often used in the context of states seceding from the United States, but it can also be used to describe individuals or groups leaving a union.