Rusty Knob Share definition Flag The act of rubbing ones sweaty ass crack on their roomies bedroom door knob. Smell it if you dare! "My roomie drank all my milk so I gave her the old Rusty Knob." Rusty Knob by Nuccuh December 1, 2011 0 0 Get merch Get the Rusty Knob mug. Buy Now — $32.95 See more merch
