The main etymology, associated with Celtic names, is from the Scots surname Gordon, from a place name, but the origin is debated:
* If the English or Scots name is from a Brythonic language (such as Old Welsh or Old Breton), then possibly from a Proto-Brythonic compound such as *gor (“spacious”) + *din (“fort”);
* If the Scots name is itself from English, then possibly from French Gourdon, derived from Gallo-Roman Latin Gordus, from Gaulish *Gordos;
* Otherwise, possibly ultimately from Old English *gor-dūn (“mud hill”) whence a habitational name.