I have wondered if there is any etymological connection to the name of the wizard Merlin in Arthurian legends.

"Merlin" of Arthurian fame comes from "Myrddin", wwh, as this passage indicates:

He was apparently given the name Emrys (or Ambrosius) at his birth in Caer-Fyrddin (Carmarthen). He only later became known as Merlin, a Latinized version of the Welsh word, Myrddin, taken from the place of his birth. Geoffrey of Monmouth is thought to have invented this form (as he did so much else), since he did not want his character to be associated with the French word, merde, meaning "excrement".