cumulonimbus vs thundercloud

cumulonimbus and thundercloud both are nouns.

Word	Noun	Adjective	Verb	Adverb
cumulonimbus	Yes	No	No	No
thundercloud	Yes	No	No	No

As nouns, cumulonimbus and thundercloud are synonyms defined as:

cumulonimbus and thundercloud: a dark cloud of great vertical extent charged with electricity; associated with thunderstorms

Other synonyms of cumulonimbus include cumulonimbus cloud.

cumulonimbus (noun)	thundercloud (noun)
a dark cloud of great vertical extent charged with electricity; associated with thunderstorms	a dark cloud of great vertical extent charged with electricity; associated with thunderstorms