dorsum ī, n, or (old) dorsus, ī, m
the back (of a beast of burden): Impositi dorso, on horseback, V.: gravius dorso onus, H.: tauri, O.—A back, ridge: dorsum esse eius iugi aequum ... silvestrem, Cs.: in dorso (montis) urbs, L.: praerupti nemoris, slope, H.: speluncae, i. e. rock, V.: Saxa ... Dorsum inmane, cliff, V.: duplici aptantur dentalia dorso, projecting irons, V.