A small cut, scraped, red, or scarred patch of skin on a mans lower back as the result of falling onto the region. Usually caused in an accident from riding a skateboard, BMX, or lesser "action sport" item such as inline skating or longboarding.
1. I fell on my back trying to ollie up a curb and got a wicked man stamp.
2. Keep on doing that rail with your shirt off and you're going to end up with a man stamp.