Blazer is a term commonly used at the bar scene at The University of Iowa. It is used to insult someone that looks like or is acting like a total fogie. Someone who loves public transportation, WWII, wearing two-piece track jumpsuits and Hawaiian shirts, and falling asleep watching baseball games is a Blazer. Think of Clint Eastwood in Gran Torino, but just the cranky old part of him, not the totally badass part.
That guy sleeping on the bus, wearing a jumpsuit, and listening to the baseball game on his headphones is a total Blazer.