conjecture vs theorise

conjecture is a noun but theorise is not a noun.

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

As verbs, conjecture and theorise are synonyms defined as:

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

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

conjecture (noun)	theorise (noun)
a hypothesis that has been formed by speculating or conjecturing (usually with little hard evidence)
reasoning that involves the formation of conclusions from incomplete evidence
a message expressing an opinion based on incomplete evidence

conjecture (verb)	theorise (verb)
to believe especially on uncertain or tentative grounds	to believe especially on uncertain or tentative grounds