Gaeligger
A Gaeligger is like an Irish person who thinks they’re the best at everything, even when they’re clearly not.
My cousin’s a Gaeligger and he thinks he’s the best at soccer, even though he missed the goal.
She called me a Gaeligger because I beat her in the math test.
He’s a Gaeligger and he still thinks he’s the strongest even though he lost to a kid in 3rd grade.