1. A penis that is deformed or does not function properly.
2. A very small penis.
Brad: Why is it taking Brandon so long to use the restroom?
Kevin: Didn't you hear? Brandon's dick doesn't work anymore after it got bit by a rattlesnake!
Brad: Shieeee, the poor sucker has a gimp dick.
Brad: Did you hear the news? Brandon's dick is only 3 cm long!
Kevin: Yea that girl that tried to suck him off told me he has a gimp dick!