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septentrĭōnālis, e, adj. [septentriones, II.], of or belonging to the north, northern, north-: pars (terrae), circulus, Varr. R. R. 1. 2, 4; Vitr. 9, 6: plaga, Sen. Q. N. 4, 5, 2: latus, id. ib. 5, 16, 6; Plin. 2, 70, 70, § 177: oceanus, id. 9, 17, 30, § 64: venti, Col. 11, 2, 21.
Plur. subst.: sep-tentrĭōnālĭa, ĭum, n., the northern regions, Plin. 11, 14, 14, § 33: Africae et Numidiae, id. 6, 34, 39, § 213: Britanniae, Tac. Agr. 10.