A person who is affiliated in a positive way with the football team the San Francisco 49ers. Generally very loyal for sticking with a franchise that seems to only get worse as the years pass by. Younger 49ers fans often burst into fits of rage and tears at the mere thought of their team while older 49ers fans have a very high likely hood of being ESPN Classic subscribers. Those who remember the good old days are likely to respond to any criticism with "We had Joe Montana" no matter what the state of the team currently is. Most 49ers fans you encounter will likely have some sort of brain damage due to banging their heads against any acceptable object after learning of the numerous financial and personnel decisions by the 49ers higher ups. They have nightmares about Terrell Owens and peaceful dreams about once again achieving .500.