Louser
Heard in Waterford and Kilkenny
A person who does nasty or cruel things to others... can also mean someone who is mean (otherwise know as a mayner).
Ya tolt yer ya wouldn't go off with her because she haves tiny diddies? You're some louser boi!
You stated you would not court her because she possesses rather diminutive breasts? You are a most frightful churl, my good fellow!