Cirrocumulus clouds are a type of high-altitude cloud that is made up of small, white, fluffy clouds that are grouped together in rows or waves. These clouds are often referred to as "sheep backs" because of their resemblance to a flock of sheep grazing in the sky. There are various synonyms for cirrocumulus clouds, such as altocumulus castellanus, which refers to the tower-like appearance of the clouds. Another synonym is cirronimbus, which describes a stormy variant of the cirrocumulus cloud. Lastly, mackerel sky is another synonym for cirrocumulus clouds as it refers to the appearance of the clouds resembling the scales on a mackerel fish.