To mistreat or neglect a person, particularly as to one for whom the actor has special responsibility by virtue of a relationship, e.g., spouse, child, elderly parent, or one for whom the actor has undertaken a duty of care, e.g., nurse-patient; 2 v. to use an object in an illegal or unreasonable manner. 3 n. The mental or physical mistreatment of a person, frequently resulting in serious emotional, mental, physical, and/or sexual injury. child abuse. 1 The intentional or neglectful abuse, wh...