The term 'grass coating' can be summarized as a type of protective covering for grass, and the crossword solution for this term is 'DEW'. DEW is a type of moisture that forms on surfaces in the early morning or evening when the air is cool. It is composed of tiny droplets of water that settle on the ground and other surfaces. DEW is often seen on grass and other plants, and it can act as a natural protective coating for the grass.