Aegina vs jellyfish

Aegina and jellyfish both are nouns.

Word	Noun	Adjective	Verb	Adverb
Aegina	Yes	No	No	No
jellyfish	Yes	No	No	No

As nouns, jellyfish is a hypernym of Aegina; that is, jellyfish is a word with a broader meaning than Aegina:

Aegina: small medusa
jellyfish: any of numerous usually marine and free-swimming coelenterates that constitute the sexually reproductive forms of hydrozoans and scyphozoans

Aegina (noun)	jellyfish (noun)
small medusa	any of numerous usually marine and free-swimming coelenterates that constitute the sexually reproductive forms of hydrozoans and scyphozoans
an island in the Aegean Sea in the Saronic Gulf	large siphonophore having a bladderlike float and stinging tentacles