What is a "Jackeen"?
The term Jackeen is generally considered to be a derogatory name for a person from Dublin (Ireland).
During the British occupation of Ireland, Dublin was considered the most British of Irish cities.
It is thought that the word comes from the fact that Dubliners were considered more loyal to British rule and the British Flag, the Union Jack. Hence the name Jackeen, or "little Jack".
Webster's dictionary defines Jackeen as;
\Jack*een"\, n. A drunken, dissolute fellow. [Ireland] --S. C. Hall.
There is a definition of the true Dubliner - a Jackeen - which requires that you, your parents and all four grandparents must have been born and bred 'between the canals' to qualify as a Jackeen.
A Jackeen is the opposite of a "Culchie"