cu·mu·lus
noun/ˈkjuːmjələs/
/ˈkjuːmjələs/
[uncountable] (specialist)- a type of thick white cloud
Topics Weatherc2积云 Oxford Collocations DictionaryCumulus is used before these nouns:- cloud
Word Originmid 17th cent. (denoting a heap or an accumulation): from Latin, ‘heap’.