behemoth vs monster

behemoth and monster both are nouns.

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

As nouns, behemoth and monster are synonyms defined as:

Other synonyms of behemoth include colossus, giant, goliath.

behemoth (noun)	monster (noun)
someone that is abnormally large and powerful	(medicine) a grossly malformed and usually nonviable fetus
a person of exceptional importance and reputation	a cruel wicked and inhuman person
	a person or animal that is markedly unusual or deformed
	an imaginary creature usually having various human and animal parts
	someone that is abnormally large and powerful