Vlach [vlɑːk] noun4 •A Wallachian. •A Romanian. •Any member of an Eastern Romance speaking group, including Romanians, Aromanians, Megleno-Romanians, and Istro-Romanians. •Any member of a Polish ethnographic group (subgroup of Silesians) living around the towns of Cieszyn and Skoczów formsVlachs