Green’s Dictionary of Slang

(Ulster) a shout.

1908		L. Doyle Ballygullion 111: An’ ivery clatther there was a guldher av an oath from him, an’ a screech from her in the bed.
1966		P. Boyle At Night All Cats Are Grey 60: He lets a gulder out of him: ‘Hey there, Iscariot!’.