acat·a·lep·sy \(ˈ)āˈkad.əlˌepsē\noun (-es) Etymology: Greek akatalēpsia, from a- a- (II) + katalēpsis comprehension, seizing + -ia — more at catalepsy 1.: an ancient Skeptic doctrine that human knowledge amounts only to probability and never to certainty 2.: real or apparent impossibility of arriving at certain knowledge or full comprehension