The term SHEET OF LOW CLOUD is a type of cloud formation that is characterized by a flat, horizontal LAYER of clouds that are usually composed of water droplets. The crossword solution for this term is STRATUS, which is a Latin word meaning 'LAYER'. STRATUS clouds are the most common type of low-level clouds and can be found in many parts of the world. They are typically gray or white in color and can form at any altitude from the ground up to 6, 500 feet.