Definition of "aversive"

aversive

adjective
comparative more aversive, superlative most aversive
1. Tending to repel, causing avoidance (of a situation, a behaviour, an item, etc.)
  Quotations
  If it is aversive to the animal and discourages behavior, it is a punishment. If it seems aversive to you but is not aversive to the animal, then it is not an effective punishment. In fact, technically, it's not even a punishment.
  2015, Ilona Rodan, Sarah Heath, editors, Feline Behavioral Health and Welfare, Elsevier Health Sciences, page 47
noun
countable and uncountable, plural aversives
1. (grammar, uncountable) A grammatical case indicating that something is avoided or feared; the evitative case.
2. (psychology, countable) An unpleasant stimulus intended to induce a change in behaviour.
  Quotations
  For general training purposes, opportunities to engage in reproductive acts are not a practical reinforcer, and using aversives that generate fear is fraught with side effects.
  2015, Ilona Rodan, Sarah Heath, editors, Feline Behavioral Health and Welfare, Elsevier Health Sciences, page 53