rationabilityEtymologyFrom Middle English racionabilite, a learned borrowing from Classical Latin ratiōnābilitās. By surface analysis, ration(able) + -ability. Piecewise doublet of reasonability.rationability means synonym of rationality or reasonability. Lexicurio rates it Sui generis — a strength score of 88 out of 100.nounSynonym of rationality or reasonability.“And, if on twenty pounds of fluid, one of humours is to be defalcated: ſhould you evaporate the whole together to one ſcruple, would you not always find in that ſcruple ſtill one grain of humours?—I will ſay no more, nor lay greater ſtreſs on that ſubjeft, but leave every one to judge for himſelf, according to his own private ſenſe, of the rationabllity of ſuch proceedings.”