Definition of "sadism"

(chiefly psychiatry) The enjoyment of inflicting pain or humiliation without pity.  examples

Achievement of sexual gratification by inflicting pain or humiliation on others, or watching pain or humiliation inflicted on others.  examples

(loosely) Deliberate or wanton cruelty, either mental or physical, to other people, or to animals, regardless of whether for (sexual) gratification.  examples