1. English, German, and Dutch: patronymic from a pet form of Nicholas (German Nikolaus).
2. Irish (County Limerick): Anglicized form of Gaelic Mac Nioceais ‘son of Nicholas’, which was taken by some Limerick families named Woulfe.
3. German (southern and Upper Rhine): from a nickname from Middle High German nickes(e), nixe ‘water sprite’.
See the Key to the Dictionary or consult the General Introduction for further explanation.