cacoethic /ˌkakəʊˈiːθik/ adjective2 •Ill-conditioned, malignant; cacoethical.From Nature's womb vitality will burst / Upon the optic and all other nerves, / To make us stare with wonder at ourselves. / The valetudinarian thus will learn / One cacoethic cause of all his woe. — 1833 •(no longer used) Of or pertaining to a cacoethes (a malignant tumour or ulcer).Take red Lead two Ounces, distill'd Vinegar two Pounds, digest for many Days; this Liquor being distill'd is us'd for a Fomentation in cacoethic Ulcers, call'd Nomae, Phagaedaenica. — 1727 formsmore cacoethic · most cacoethic