theorizer vs theoriser

theorizer and theoriser both are nouns.

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

As nouns, theorizer and theoriser are synonyms defined as:

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

Other synonyms of theorizer include idealogue, theoretician, theorist.

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