Definition - What does Knee Pillory mean?
Knee pillory is the act of restraining an individual in a position on the knees where the head and arms are in a device. Knee pillory might also be referred to as kneeling pillory or a kneeling stock. The bench-style device is knelt over then the head and arms are retrained to ensure the victim cannot move and will remain in the kneeling position.
Kinkly explains Knee Pillory
Pillory was originally used as a way of publicly humiliating an individual. The pillory was often used as a flagellation post, and often other things would be thrown or the victim tortured in other ways. The practice made it into BDSM play as a device to restrain a submissive to be tortured or flogged.