abbreviation for m-hairyass / meathair / anything you can think of that has the "hair" sound in it for an insult.
mher has a m-hairy ass.
If something is just overwhelming or no answer is necessary. Just reply with "Mher" also can be used as you would use an "eh" or an "erm". You may wish to randomly shout "mher" when out with friends.
Friend: hiya, wna get some pizza?
You: Mher. ok.
You: Mher, hi.
Friend: Hiya, mher.