Roussillonese noun 2adjective 1 noun2 •A native or inhabitant of the Roussillon region. •The northern dialect of the Catalan language spoken in Roussillon and North-Eastern Catalonia. adjective1 •Of, from or relating to the Roussillon region, approximately coterminous with the Pyrénées-Orientales department, Occitania, France but originally part of Catalonia; or the dialect of Catalan spoken there.