theorise vs theorize

theorise and theorize both are verbs.

Word	Noun	Adjective	Verb	Adverb
theorise	No	No	Yes	No
theorize	No	No	Yes	No

As verbs, theorise and theorize are synonyms defined as:

theorise and theorize: to believe especially on uncertain or tentative grounds

Other synonyms of theorise include conjecture, hypothecate, hypothesise, hypothesize, speculate, suppose.

theorise (verb)	theorize (verb)
to believe especially on uncertain or tentative grounds	to believe especially on uncertain or tentative grounds
	form or construct theories
	construct a theory about