1. n. interactions in which one person behaves in a cruel, violent, demeaning, or invasive manner toward another person or an animal. The term most commonly implies physical mistreatment but also encompasses sexual and psychological (emotional) mistreatment.
2. vb. to subject a person or animal to such treatment.
3. n. see substance abuse.
4. n. colloquially, the misuse of a substance to the extent that it causes the individual difficulty, whether or not it meets a foormal diagnosis or substance abuse. —abuser n.