The term 'Tough and Stringy' can be summarized by the crossword solution 'SINEWY, ' which is a six-letter word. SINEWY is an adjective that describes something as having tough, strong fibers or cords, often used to refer to muscles. It is derived from the Latin word sinus, meaning 'CORD' or 'STRING.' SINEWY is often used to describe the texture of certain meats, such as beef jerky, which is known for its toughness and stringiness.