behemoth vs heavyweight

behemoth and heavyweight both are nouns.

Word	Noun	Adjective	Verb	Adverb
behemoth	Yes	No	No	No
heavyweight	Yes	No	No	No

As nouns, behemoth and heavyweight are synonyms defined as:

behemoth and heavyweight: a person of exceptional importance and reputation

Other synonyms of behemoth include colossus, giant, titan.

behemoth (noun)	heavyweight (noun)
someone that is abnormally large and powerful	A weight class division in combat sports, often the heaviest.
a person of exceptional importance and reputation	a person of exceptional importance and reputation
	a professional boxer who weighs more than 190 pounds
	a wrestler who weighs more than 214 pounds
	a very large person; impressive in size or qualities
	an amateur boxer who weighs no more than 201 pounds