Cumulus clouds are clouds which have flat bases and are often described as "puffy", "cotton-like" or "fluffy" in appearance. Their name derives from the Latin cumulo-, meaning heap or pile.

What does cumulus cloud mean?

[ (kyooh-myuh-luhs) ] Large, white, puffy clouds that generally appear during fair weather, although they also form thunderheads on hot days. Some carry rain.

What is cumulus and cumulonimbus clouds?

Cumulus clouds are formed due to the vertical flow of air. Cumulus clouds appear huge and are dome-shaped. Cumulonimbus clouds appear like huge mountain and have an anvil shaped top portion. ... These are dark coloured clouds which cause thunder and lightening.