fictitious character vs Argonaut

fictitious character and Argonaut both are nouns.

Word	Noun	Adjective	Verb	Adverb
fictitious character	Yes	No	No	No
Argonaut	Yes	No	No	No

fictitious character (noun)	Argonaut (noun)
an imaginary person represented in a work of fiction (play or film or story)	cephalopod mollusk of warm seas whose females have delicate papery spiral shells
	(Greek mythology) one of the heroes who sailed with Jason in search of the Golden Fleece