From the Old Norse personal name Rögnvaldr (composed of regin ‘advice, decision’ (also, ‘the gods’) + valdr ‘ruler’). This name was regularly used in the Middle Ages in northern England and Scotland, where Scandinavian influence was strong. It is now widespread throughout the English-speaking world.
English (Merseyside and Cheshire): probably a habitational name from a place in Cheshire named Big Low in the township of Rainbow. This place name is not on early record; it means ‘big mound’, from early Modern English big + low ‘mound’, ‘hill’ (Old English hlāw).