Argonaut vs nautilus

Argonaut and nautilus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Argonaut	Yes	No	No	No
nautilus	Yes	No	No	No

As nouns, Argonaut and nautilus are synonyms defined as:

Argonaut and nautilus: cephalopod mollusk of warm seas whose females have delicate papery spiral shells

Other synonyms of Argonaut include Argonauta argo, paper nautilus.

Argonaut (noun)	nautilus (noun)
cephalopod mollusk of warm seas whose females have delicate papery spiral shells	cephalopod of the Indian and Pacific oceans having a spiral shell with pale pearly partitions
(Greek mythology) one of the heroes who sailed with Jason in search of the Golden Fleece	cephalopod mollusk of warm seas whose females have delicate papery spiral shells
	a submarine that is propelled by nuclear power