The term 'TOP SELLER' can be summarized by two crossword solutions: HIT (3 letters) and TOYSHOP (7 letters). HIT is an acronym for 'high-intensity training, ' which is a type of exercise that involves short bursts of intense physical activity. TOYSHOP is a store that specializes in selling toys, games, and other items for children. A TOP SELLER in either of these contexts would refer to a product or service that is highly sought after and has high sales.