The crossword solution for the term 'flow smoothly' is 'GLIDE'. Gliding is a form of movement in which an object or organism moves smoothly and effortlessly across a surface. It is often used by animals, such as birds, to move through the air, and by humans to move across water or ice. Gliding can also be used to describe the movement of objects through a liquid or gas, such as a boat moving through water or a balloon floating through the air.