stargazer vs astronomer

stargazer and astronomer both are nouns.

Word	Noun	Adjective	Verb	Adverb
stargazer	Yes	No	No	No
astronomer	Yes	No	No	No

As nouns, stargazer and astronomer are synonyms defined as:

Other synonyms of stargazer include uranologist.

stargazer (noun)	astronomer (noun)
heavy-bodied marine bottom-lurkers with eyes on flattened top of the head	a physicist who studies astronomy
a physicist who studies astronomy
someone indifferent to the busy world