Jock straps, also known as athletic supporters, are an item of clothing worn by athletes to provide support for the groin area. The term 'JOCK strap' is derived from the word 'JOCK, ' which is a slang term for an athlete. The crossword solution for the term 'JOCK straps' is 'REINS, ' which is a type of strap used to control a horse. REINS are typically made of leather and are attached to a bridle or harness. In the same way that REINS are used to control a horse, JOCK straps are used to provide support and stability to the groin area of athletes.