The crossword solution for the term 'sinuous shape' is ESS, which stands for 'elongated and curved'. A sinuous shape is a type of shape that is characterized by its elongated and curved nature. It is often used to describe objects or lines that are winding, curving, and meandering. Sinuous shapes are often found in nature, such as in rivers, mountains, and coastlines. They can also be found in art, architecture, and design.