† exˈcidionObs.rare—1. [ad. L. excidiōnem destruction, believed to be f.exscid-, exscindĕre to extirpate, destroy, f.ex- out + scindĕre to cut.] Extirpation, destruction. 1490Caxton Eneydos i. (1890) 11 Troye was enuyronned in fourme of siege, and of excidyon, by Agamenon.