Lewis & Short

dē-sub, praep. c. abl., below, beneath (late Lat.; cf. desuper): desub Alpibus, id est, desub ipsis Italiae faucibus, Flor. 2, 3, 2: desub oculo, Veg. Vet. 2, 19: desub rivo, Innocent. de Cas. liter. p. 226 ed. Goes.: desub se, id. ib. 223: lucernam desub modio ejecit, Fulg. Mythol. 3, 6.