Deliberate cruelty, either mental or physical; also refers to cruelty inflicted upon animals, regardless of gratification
Sadism is a type of behaviour in which a person obtains pleasure from hurting other people and making them suffer physically or mentally. Psychoanalysts tend to regard both sadism and masochism as arising from childhood deprivation. + sadist sadists sad·ist The man was a sadist who tortured animals and people. Psychosexual disorder in which sexual urges are gratified by inflicting pain on another person. The term was coined in reference to the marquis de Sade, who chronicled his own such practices. Sadism is often linked to masochism, and many individuals who have one tendency also have the other
{i} derivation of pleasure from the suffering of others; sexual perversion in which a person attains sexual pleasure by causing pain to his partner (Psychiatry)