When someone looks way too old for their age, possibly because of long term drug abuse or some other form of hard living. The term was first used on a Kanye West blog entry, where he described his older looking appearance on the cover of a magazine. The term has since been mostly used on dlisted.com to describe celebrities who look ridiculously old for their age.
Damn, Jenny and I are the same age but she looks at least 10 years older than me. That's some Benjamin Button's shit right there.