Aquarius vs doer

Aquarius and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
Aquarius	Yes	No	No	No
doer	Yes	No	No	No

As nouns, doer is a hypernym of Aquarius; that is, doer is a word with a broader meaning than Aquarius:

Other hypernyms of Aquarius include actor, worker.

Aquarius (noun)	doer (noun)
the eleventh sign of the zodiac; the sun is in this sign from about January 20 to February 18	a person who acts and gets things done
a zodiacal constellation in the Southern Hemisphere; between Capricornus and Pisces
(astrology) a person who is born while the sun is in Aquarius