Lewis & Short

1. Marpessus or Marpēsus, i, f., = Μάρπησσος (another form of Μάρμησσος v. Marmessus), a town in the Troas, on Mount Ida, home of the Erythrean Sibyl, Varr. ap. Lact. 1, 6, 12.
Hence, adj.: Marpessĭus (-ēsius), a, um, of or belonging to Marpessus in the Troas, Marpessian, Tib. 2, 5, 67 Drisen.