A term used to indicate you got over on a situation, particularly when dealing with the government or other agencies/companies of authority. Derived from Shameless.
“Did you pay your ticket for when they caught you speeding?”
“Naw, I pulled a Gallagher and got it dismissed.”
“The return window was already closed but I Gallagherd the shut out of them and got my money back.”
To be a 6.5 million dollar third line checking winger, who doesn't contribute much at all and loves to whine.
I can't imagine having a Gallagher on my team. What a waste of money and time.