Neapolitan (n.)

early 15c., "native or resident of Naples," literally "of Naples," from Latin Neapolitanus, from Neapolis (see Naples); it preserves in English the Greek name of the city. As an adjective from 1590s. As a type of ice cream, from 1871; originally meaning both "ice cream of three layers and flavors" and "ice cream made with eggs added to the cream before freezing." In early 18c., Neapolitan consolation meant "syphilis."