LUG stands for Linux User Group. 1. Lug: Alternative name for Lugh, a Celtic God. The Shining One, and a real cleverclogs in all the Crafts and Arts. 2. In Romans: Mercury, in Gaulish/British: Lugus, in Welsh: Lleu. 3. Lugh is a god of craftsmanship or a solar deity, also known as Lamfhada. As leader of the Tuatha De Danann, Lugh defeated the Fomorians at the Second Battle of Magh.