The term 'KIND OF CLOUD' can be broken down into three crossword solutions: WAR (3 letters), NIMBUS (6 letters), and OORT (4 letters). WAR clouds are a type of cumulonimbus cloud that is associated with thunderstorms. NIMBUS clouds are a type of low-level cloud that is characterized by its gray, dark, and rainy appearance. Oort clouds are a type of cloud that is located at the outermost edge of the Solar System and is composed of icy particles.