Etymologies
The name "Bertilak" may derive from bachlach, a Celtic word meaning "churl" (i.e. rogueish, unmannerly). Alternatively it may derive from "bresalak", meaning "contentious". The Old French word bertolais translates as "Bertilak" in the Arthurian tale Merlin from the Lancelot-Grail Cycle of Arthurian legend. Notably, the 'Bert-' prefix means 'bright', and the '-lak' can mean either 'lake' or "play, sport, fun, etc". "Hautdesert" probably comes from a mix of both Old French and Celtic words meaning "High Wasteland" or "High Hermitage". It may also have a connection with desirete meaning "disinherited" (i.e. from the glory of the Round Table).
Read more about this topic: Green Knight