The term 'BIG TOP SHOW' is a reference to a CIRCUS, which is a form of entertainment that typically involves acrobats, clowns, and trained animals performing for an audience. The crossword solution for this term is 'CIRCUS, ' which is a six-letter word. A big top show is a type of CIRCUS performance that takes place in a large tent, often referred to as a 'big top.' This type of show usually features a variety of acts, including clowns, acrobats, and animal performances.