The word Gall can have two meanings. It can refer to a foreigner, especially from countries that have at some stage invaded Ireland. It is probably the word the Irish once used to refer to Anglo-Normal invaders who had originated from Gaul (= Nothern France). It can also refer to a person who is from Ireland but is not rooted in Ireland's native Gaelic culture and identifies more closely with the Anglo-Irish tradition. It is not a very polite word but it can be used jokingly.