astrologer vs astrologist

astrologer and astrologist both are nouns.

Word	Noun	Adjective	Verb	Adverb
astrologer	Yes	No	No	No
astrologist	Yes	No	No	No

As nouns, astrologer and astrologist are synonyms defined as:

astrologer and astrologist: someone who predicts the future by the positions of the planets and sun and Moon

astrologer (noun)	astrologist (noun)
someone who predicts the future by the positions of the planets and sun and Moon	someone who predicts the future by the positions of the planets and sun and Moon