geometrician vs mathematician

geometrician and mathematician both are nouns.

Word	Noun	Adjective	Verb	Adverb
geometrician	Yes	No	No	No
mathematician	Yes	No	No	No

As nouns, mathematician is a hypernym of geometrician; that is, mathematician is a word with a broader meaning than geometrician:

geometrician (noun)	mathematician (noun)
a mathematician specializing in geometry	a person skilled in mathematics