Bad treatment is a term used to describe any kind of mistreatment or maltreatment of an individual. ABUSE and illusage are two words that can be used to describe bad treatment. ABUSE is defined as the improper usage or treatment of an entity, often to unfairly or improperly gain benefit. Illusage is defined as the act of treating someone badly or unfairly. Both terms are used to describe the mistreatment of an individual, whether it be physical, mental, or emotional.