An adjective to describe someone incredibly ugly. They typically look like their face has been hit with a shovel...many times. Usually, a person who is a Coughlin has long dark hair and even though its long, still tucks it behind his ear. No one loves him.
Dude, Patrick just walked into the bar, he looks like such a Coughlin tonight!
After the mob attacked that dude, he was a Coughlin the rest of his life.