theoriser vs theorizer

theoriser and theorizer both are nouns.

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

As nouns, theoriser and theorizer are synonyms defined as:

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

Other synonyms of theoriser include idealogue, theoretician, theorist.

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