cumulonimbus Syllabification: (cu·mu·lo·nim·bus)Pronunciation: /ˌkyo͞omyəlōˈnimbəs/Definition of cumulonimbus noun (plural cumulonimbi /-ˈnimbī, -bē/) Meteorology a cloud forming a towering mass with a flat base at fairly low altitude and often a flat top, as in thunderstorms. cumulonimbus in other Oxford dictionaries Definition of cumulonimbus in the British & World English dictionary
