Altanus, altáni, pen. prod. Genus venti. Plin. An eastern winde.
Lewis and Short: Latin dictionary
altānus, i, m., a south-southwest wind, between the Africus and Libonotus, Vitr. 1, 6, 10, cf. Plin. 2, 43, 44, 114 (acc. to Isid. Orig. 13, 11 and Serv. ad Verg. A. 7, 27, the sea winds were so called quod ab alto spirant).