The correct definition of Aversive conditioning is the form of treatment that consists of repeated pairings of a stimulus with a very unpleasant stimulus.
Behaviorists researchers had applied techniques of aversive conditioning, also called aversive therapy for testing animal learning process, it requires the induction of some stimulus with something simultaneously unpleasant and this may lead the behavior to be stopped. This therapy can be used for nail biting, adding some unpleasant flavor in some product that goes into the nail, this may lead the person to stop biting her nails.