A knob knuckle is the term used for accidentally grabbing a testicle during the act of
male masturbation, then yanking it swiftly up into the centre of an erect penis, giving a knee cap, or knuckle
type appearance in the centre of the shaft.
- To knob knuckle someone is to cause them pain through some form of passive aggressive behaviour, often resulting in some subtle yet severe psychological trauma.
- To be a knob knuckle is to perform activities in a careless fashion, not paying full attention to the task in hand.