Domestic Violence has many definitions.
Domesticviolence.org: "behavior used by one person in a relationship to control the other."
Merriam-Webster's Dictionary: "the inflicting of physical injury by one family or household member on another or the repeated or habitual pattern of such behavior."
The Department of Justice: "a pattern of abusive behavior in any relationship that is used by one partner to gain or maintain power and control over another intimate partner. Domestic violence can be physical, sexual, emotional, economic, or psychological actions or threats of actions that influence another person. This includes any behaviors that intimidate, manipulate, humiliate, isolate, frighten, terrorize, coerce, threaten, blame, hurt, injure, or wound someone."