N. Wales general street / housing estatecatch-all term meaning, variously, to 'talk nonsense'; 'to corner someone and batter their head with words'; to rap}
"It was hell of a shady last night, I copped a hell of a moidering off that girl I shagged last Saturday"
A term used in Ireland, the North of England and some parts of Wales to describe a situation when a person is talking at them unnecessarily, and it is irritating them.
Derives from the Irish of myther (say that word in your head in an Irish accent and all will be clear).