Olympian vs Greek deity

Olympian and Greek deity both are nouns.

Word	Noun	Adjective	Verb	Adverb
Olympian	Yes	Yes	No	No
Greek deity	Yes	No	No	No

Olympian (noun)	Greek deity (noun)
an athlete who participates in the Olympic games	a deity worshipped by the ancient Greeks
a classical Greek god after the overthrow of the Titans

Olympian (adjective)	Greek deity (adjective)
of or pertaining to the greater gods of ancient Greece whose abode was Mount Olympus
of the region of Olympia in Greece or its inhabitants