Old English walu "ridge, bank" of earth or stone, later "ridge made on flesh by a lash" (related to weal, n.2); from Proto-Germanic *walo (cognates: Low German wale "weal," Old Frisian walu "rod," Old Norse völr "round piece of wood," Gothic walus "a staff, stick," Dutch wortel, German wurzel "root"), from PIE root *wel- (3) "to turn, roll" (see volvox). The common notion perhaps is "raised line." Used in reference to the ridges of textile fabric from 1580s. Wales "horizontal planks which extend along a ship's sides" is attested from late 13c.