Green’s Dictionary of Slang

(Irish) a general term of abuse, loudmouth.

1951		S.H. Bell December Bride 32: ‘He’s a crabbit ould blirt, too,’ grumbled the servingman.
1966		P. Boyle At Night All Cats are Grey 43: ‘Ye little blirt,’ he roared. ‘I’ll put manners on ye.’.
1977		(con. 1930s) S. McAughtry Sinking of the Kenbane Head 35: Try it on somebody your own size, ya blirt ye.
1993		S. Heaney Midnight Verdict 32: You’ve had your warnings, you cold-rifed blirt.