Green’s Dictionary of Slang

(Ulster) to shout.

1979		J. Morrow Confessions of Proinsias O’Toole 22: I had two Powers down me and was starting on a third before they guldered the last stanza.
1996		Sun. Trib. (Dublin) 2 June n.p.: There was too much screaming and guldering and I was concerned that all that tension would distress the baby [BS].