theorist vs theorizer

theorist and theorizer both are nouns.

Word	Noun	Adjective	Verb	Adverb
theorist	Yes	No	No	No
theorizer	Yes	No	No	No

As nouns, theorist and theorizer are synonyms defined as:

theorist and theorizer: someone who theorizes (especially in science or art)

Other synonyms of theorist include idealogue, theoretician, theoriser.

theorist (noun)	theorizer (noun)
someone who theorizes (especially in science or art)	someone who theorizes (especially in science or art)