What is "lugus"

Lugus was a deity of the Celtic pantheon. His name is rarely directly attested in inscriptions, but his importance can be inferred from place names and ethnonyms, and his nature and attributes are deduced from the distinctive iconography of Gallo-Roman inscriptions to Mercury, who is widely believed to have been identified with Lugus, and from the quasi-mythological narratives involving his later cognates, Welsh Lleu Llaw Gyffes (Lleu of the Skillful Hand) and Irish Lugh Lámhfhada (Lugh of the Long Arm).