What is the origin of the name of the city Dundee?

There are two possible explinations for the name Dundee, a city in Scotland. It is either derived from the the Latin: 'Donum Dei' which translates as 'Gift of God'. It may also derive from the Scots Gaelic Dun Deagh which translates as 'Fort of Fire' - a reference perhaps to the topography of the city itself.