The term 'Sheath Feature' can be summarized by the crossword solution 'SLIT, ' which is a four-letter word. A SLIT is a long, narrow cut or opening in a surface or object, often used to hold something else in place. Slits are commonly found in clothing, such as skirts and dresses, and are also used in other materials such as leather and paper. Slits can also be used to create decorative patterns or to provide ventilation.