colossus vs monster

colossus and monster both are nouns.

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

As nouns, colossus and monster are synonyms defined as:

Other synonyms of colossus include behemoth, giant, goliath.

colossus (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