In Scottish Gaelic, dubh has more than one meaning. Traditionally, it means “black.” However, it can also mean “hidden.” In the case of a Sgian Dubh, it is more likely to mean hidden, as the Sgian Dubh is worn partially hidden in a kilt hose or sock. Sgian means knife. So, a Sgian Dubh is a hidden knife or a black knife, depending on your translation.