"eager desire to possess something," mid-15c., from Anglo-French cupidite and directly from Latin cupiditatem (nominative cupiditas) "passionate desire, lust; ambition," from cupidus "eager, passionate," from cupere "to desire." This is perhaps from a PIE root *kup-(e)i- "to tremble; to desire," and cognate with Sanskrit kupyati "bubbles up, becomes agitated;" Old Church Slavonic kypeti "to boil;" Lithuanian kupėti "to boil over;" Old Irish accobor "desire."
Despite the primarily erotic sense of the Latin word, in English cupidity originally, and still especially, means "desire for wealth."