From My Sisters' Place website www.mysistersplaceny.org
National Domestic Violence Hotline
Please don't call it "an abusive relationship". It isn't the relationship that's abusive, its the perpetrator. I prefer to call it "intimate partner abuse", but that's a mouthful. DV (domestic violence) seems a fair shortcut, though the realtionship isn't always domestic and there isn't always physical violence.
My prefered definition: Domestic violence is a pattern of behavior chosen and used by an abuser to control his/her victim. It can include physical violence, emotional, mental, and/or verbal abuse, humiliation (public and private), sexual abuse/rape, and economic abuse. The abuse keeps the victim in a state of fear and prevents her/him from making decisions that defy the wishes of the abuser. (I'll address the "why doesn't she leave" question another day.) DV occurs across lines of race, class, ehtnicity, and family configuraton. Men, women, and trans folks can be victims. It happens in strait, gay, and trans relationships. No group is immune.
SO, if you're trying to explain to someone who is not being abused why they should care, here is one more reason that appeals to self-interest: