What is "dusios"

In the Gaulish language, Dusios was a divine being among the continental Celts who was identified with the god Pan of ancient Greek religion and with the gods Faunus, Inuus, Silvanus, and Incubus of ancient Roman religion. Like these deities, he might be seen as multiple in nature, and referred to in the plural (dusioi), most commonly in Latin as dusii. Although the Celtic Dusios is not described in late-antique sources independently of Greek and Roman deities, the common functionality of the others lay in their ability to impregnate animals and women, often by surprise or force. Dusii continue to play a role in the magico-religious belief systems of Gaul and Francia as a type of incubus in early-medieval paganism and Christianity.