octopod vs Argonaut

octopod and Argonaut both are nouns.

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

As nouns, Argonaut is a hyponym of octopod; that is, Argonaut is a word with a more specific, narrower meaning than octopod:

octopod: a cephalopod with eight arms but lacking an internal shell
Argonaut: cephalopod mollusk of warm seas whose females have delicate papery spiral shells

Other hyponyms of octopod include devilfish, octopus, Argonauta argo, nautilus, paper nautilus.

octopod (noun)	Argonaut (noun)
a cephalopod with eight arms but lacking an internal shell	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