What is "teyrnon"

In Welsh tradition, Teyrnon Twryf Lliant is the lord of Gwent and the foster-father of the divine son, Pryderi. He appears most prominently in Pwyll Pendefig Dyfed, the first branch of the Mabinogi, but also features briefly in the early Arthurian tale, Culhwch ac Olwen as a knight of King Arthur's. The name Teyrnon is widely acknowledged as deriving from the Brythonic *Tigernonos, "great lord".