Originally Posted by Wikipedia

Donald is a male given name. It is an anglicized form of the Scottish Gaelic or Irish Gaelic personal name Domhnall, Dòmhnall, Dumhnuil and/or Dónall. This contains the elements dumno meaning "world" and val meaning "rule" (viz. "ruler of the world").[citation needed] Compare Dumnorix. A short form of Donald is Don; pet forms include Donnie and Donny, and in Scotland Dolly. The name Dónall is also the Irish for Daniel.