Lleu Llaw Gyffes

Lleu Llaw Gyffes (Welsh pronunciation: [ˈɬəɨ ˈɬau ˈɡəfɛs], sometimes misspelled Llew Llaw Gyffes) is a hero of Welsh mythology. He appears most prominently in the Fourth Branch of the Mabinogi, the tale of Math fab Mathonwy, which tells the tale of his birth, his marriage, his death, his resurrection and his accession to the throne of Gwynedd. He is a warrior and magician, invariably associated with his uncle Gwydion.

He is widely understood to be the Welsh equivalent of the Irish Lugh and the Gaulish Lugus. It has been suggested that Lleu, like Pryderi, is related to the divine son figure of Mabon ap Modron.

The name Lleu is derived from Proto-Celtic *Lugus, the exact meaning (and etymology) of which is still a matter of scholarly debate.

For many years the name *Lugus was thought to have been derived from the Proto-Indo-European root *leuk-, "light", and thus he was considered a sun god. This etymology has been dismissed because Proto-Indo-European *k did not under any known circumstances become *g- in Proto-Celtic, but remained *k. The direct descendent of the Proto-Indo-European root *leuk- (‘white light’) in Proto-Celtic is *leuk- as in the name of the Gaulish lightning god Loucetios.

Proto-Celtic *Lugus may be related to the root of the Proto-Celtic *lug-rā ‘moon’ (the origin of Welsh lloer, though Peter Schrijver suggests an alternative etymology for lloer, from Common Celtic *lus-rā, where the root would be cognate with that of Latin luridus [earlier *lus-idus] "pale yellow"). Another possibility is Proto-Indo-European *leug- meaning "blackness, dimness, darkness" (thought by Pokorny to be the root of the ill-attested Gaulish word lugos "raven"), or *leug- "swamp, peat bog". Proto-Celtic *Lugus may equally be related to Proto-Celtic *lug- meaning "oath, pledging, assurance" on the one hand and "deceive" on the other (derived from Proto-Indo-European *leugh- ‘avowal, deception’). Juliette Wood interprets his name as deriving from Proto-Celtic *lug-, "oath", which would support this identification of Mercury as a god of contracts.

...
Wikipedia