Boy name origins & meanings Old English : Dark waterEnglish : Worthy Boy name variations Douglas Douglass Doug Dougie Dug Dougal Dugald Dougles Dugaid Duglass Doogan Doogen Dougan Dougen Douggan Douggen Dugen Duggan Family name origins & meanings Irish : reduced Anglicized form of Gaelic Ó Dubhagáin ‘descendant of Dubhagán’, a byname representing a double diminutive of dubh ‘black’, ‘dark’ (see Duff).Irish : reduced Anglicized form of Ó Duibhginn (see Deegan).