Of Scottish origin: Anglicized form of two different Gaelic names, Cinaed and Cainnech. The former was the Gaelic name of Kenneth mac Alpin (d. 858), first king of the united Picts and Scots. The latter survives today in Scotland as the common Gaelic name Coinneach. Since early in the 20th century Kenneth has been in regular use and enjoyed great popularity as a given name well beyond the borders of Scotland.
German and Jewish (Ashkenazic): nickname for someone who performed wonders, from German Wunder ‘miracle’, Middle High German wunderære. The Jewish name is mainly of ornamental origin. The German name can also be from a nickname for a curious or inquisitive person, from Middle High German wunder ‘curiosity’, ‘astonishment’.