humongous vs thumping

humongous is not a noun while thumping is a noun.

Word	Noun	Adjective	Verb	Adverb
humongous	No	Yes	No	No
thumping	Yes	Yes	No	No

As adjectives, humongous and thumping are synonyms defined as:

Other synonyms of humongous include banging, walloping, whopping.

humongous (noun)	thumping (noun)
	a heavy dull sound (as made by impact of heavy objects)

humongous (adjective)	thumping (adjective)
(used informally) very large	(used informally) very large