A condition most commonly pertaining to young men wherein every female he is attracted to automatically kicks him to the friend zone because she thinks of him as an older brother. This often occurs when a girl mistakes being a gentleman or a nice guy for being a pussy. Some girls go so far as to designate these poor bastards as their go-to "Shoulders to Cry on" when they repeatedly get shit on by the assholes they do date. -See the film "Sexdrive"
"Dude did you get anywhere with her last night?"
"No man, she told me it will never happen cause I'm too much like a brother to her and she doesn't want to ruin our friendship. I must have Goofy Older Brother Syndrome."