West Brit (abbreviation for West British) is a pejorative term for an Irish person perceived by some of his countrymen as too anglophile in matters of culture or politics.^[1]

West Brit - Wikipedia, the free encyclopedia

"West Brit" is today used by Irish people to criticise a variety of perceived faults:

• A pejorative term for someone from Dublin.
• Taking a view of Irish history which highlights perceived positive aspects of British influence in Ireland, or criticizing Irish nationalist rebellions
• Cultural cringe: following British popular culture, while appearing embarrassed by or disdainful of aspects of Irish culture, such as the Irish language, Gaelic games or Irish traditional music
• Opposition or indifference to a United Ireland (see Partitionism) or to Irish republicanism
• Support (or alleged support) for neo-Unionism
• In sporting terms, used to describe fans of English football clubs, particularly those who dismiss or ignore their local League of Ireland club.

Generally a humorous or sarcastic reference to someone who is perceived as being a bit posh, well spoken, or socially aspiring ... its the post colonial way to fight off colonial cultural assimilation...  

Index of Frank's Diaries