Jackeen

n. (Irish usage) city dweller (especially a resident of Dublin); Dubliner who is considered as educated and well-read (Irish Slang); drunken and immoral person (Irish Slang)

Jackeen is a mildly pejorative term for someone from Dublin, Ireland. The word has been defined as A drunken, dissolute fellow by Webster in 1913.An incorrect but common suggested origin of the word comes from John Bull, the personification of England. Due to its proximity and long historical ties to Britain, Irish people outside of the Pale thought that Dubliners wanted to be English. John Bull became Jack Bull and, using the Irish suffix -ín meaning small, Jack became Jackeen. Therefore, Jackeen literally means Little Jack or "minibrit".
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(n.)
A drunken, dissolute fellow.