Someone who, although they have never been to ireland, profoundly believes themselves to be in some way inherently irish. Maybe their great-granny once saw dublin from a boat, or maybe they just like the colour green, who knows.
Wannabe
irishness is most common in the USA, although they pop up everywhere. Things
wannabe Irish people like: funding the
IRA, talking endless bollocks about Ireland, and using some appropriated version of irish identity to excuse behaving like a drunken twat.