Given to conjecturing or to depending on mere conjecture: as, a conjectural critic.

Depending on conjecture; springing from or implying a guess or conjecture; problematical: as, a conjectural opinion; a conjectural emendation of a text.

adjective. Dependent on conjecture; fancied; imagined; guessed at; undetermined; doubtful.

adjective. In the nature of a conjecture, or based on a conjecture.

noun. Something that is conjectural; a conjecture.

adjective. based primarily on surmise rather than adequate evidence

"The only physical cause for the practice which suggests itself to me and that must be owned to be purely conjectural, is that within the Sotadic Zone there is a blending of the masculine and feminine temperaments, a crasis which elsewhere occurs only sporadically."

unquestionable  

supposed  

theoretic  theoretical  

allegorical  attributable  autobiographical  baseless  biographical  

abstract  academic  arguable  armchair  at issue