spodnji kašelj was mentioned in written sources together with neighboring zgornji kašelj in 1360 as "niederchaeschel" and "kaeschel" (and as "geschel" in 1421, "(ober) kassel" in 1436, and "kaschell" in 1496). the name is derived from german "kassel" and it is likely that the german name is derived from latin "castellum" 'castle', referring to one or both castles on kašelj hill east of the settlement. however, it is also possible that the name is derived from latin "casale" 'peasant house, peasant settlement'. in the past the german name was "unterkaschel".