The term 'turnstile' is a type of GATE that is commonly used in public places such as stadiums, subway stations, and amusement parks. It is designed to control the flow of people entering and exiting an area. The crossword solution for turnstile is 'GATE, ' which is a four-letter word. A GATE is a structure that provides an entrance or exit to a place, and it can be opened and closed to control access. Turnstiles are a type of GATE that is specifically designed to control the flow of people.