trĭ-sulcus — Lewis & Short
trĭ-sulcus, a, um (form trĭsulcis, e, adj.ter (having three furrows),
Fulg. Rusp. Ep. 9),lingua (serpentis),Verg. A. 2, 475; Plin. 11, 37, 65, § 171:
sermo, of the serpent in Paradise,Prud. Ham. 203:
ordine trisulco quatit ora fragor, of the teeth,Val. Fl. 2, 500: fulmen, Varr. ap. Non. 448, 20; cf. Fest. p. 352;
also called Jovis telum trisulcum,Ov. Ib. 467:
ignes,id. M. 2, 848:
Sicilia,Claud. Rapt. Pros. 1, 145: fores, folding in three parts, Varr. ap. Serv. Verg. A. 1, 449:
ramus,threeforked, Pall. Mart. 10, 24.