What does it mean? I always thought it meant someone who is an ass. Please tell us.
Yes, that’s what it means in Pittsburghese, but I recall one of the OANN commentators (not Graham, but an Italian name that escapes me) a few years ago had a segment called “Jagoff of the Week” or some such thing. He was from Pittsburgh, and used the term the way most Pittsburghers understand it to mean.
He said at one point he received e-mail from shocked viewers from other parts of the country who thought the term had something to do with the vulgarity “j*ack-off”, and threatened to turn off the show because it wasn’t family friendly.