Dick Dust (verb): The human male act of brushing said male's penis along side some body part of human female in close proximity. Commonly done by middle school boys to girls in science class where both male and female students stand by each other in close quarters playing with beakers and Erlenmeyer flasks.
Not to be confused with the "womb broom" which is the same as the dick dust but where the male/female species role is reversed.
Susy: "Hey, what's that I feel on my backside? Oh, it's just Johnny trying to walk by innocently"