Recorded in several forms including Gwilt, Gwyllt, and Wyllt, this is a true Welsh surname. It derives from the pre 7th century word "gwyllt" meaning wild. It was originally either a baptismal personal name, or more likely a medieval nickname for a "wild man", or given the robust humour of the period, probably the reverse! Nicknames form a large percentage of almost all surname groups in every language and country, and indeed an even higher proportion in the Gaelic where they are the norm. It is always a source of confusion as to why such names were so popular or even why they have survived at all, but without being present when these names were created and without a precise knowledge of actual meanings seven hundred or more years ago, which we do not possess with certainty, it has to be guesswork. Sometimes confused and overlapping in spelling with the English nickname surname Wild or Wilde, this surname is well recorded from the 16th century in the border counties of England and Wales. These recordings include Howel Wyllt of LLantrithyd, Glamorgan, in 1593, Maurice Gwilt of Chirbury in 1664, and Richardus Quilt of Clunbury in 1750, both from Shropshire.