cumulonimbus cloud vs thundercloud

cumulonimbus cloud and thundercloud both are nouns.

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

As nouns, cumulonimbus cloud and thundercloud are synonyms defined as:

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

Other synonyms of cumulonimbus cloud include cumulonimbus.

cumulonimbus cloud (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