Abuse, as defined here at Unholy Charade is:

A habitual pattern of behaviors that proceed from a mind whose very essence and nature is a profound attitude of entitlement to unauthorized, malignant, power and control over the person or persons the abuser targets. Domestic abusers target their spouse or another individual with whom they are romantically involved. Spiritual abusers target persons in a religious setting such as a local church. Sexual abusers strive for power and control over victims for sexual exploitation. Many times these categories will overlap in one abuser.

The abuser by nature knows how to use an arsenal of psychological, verbal, or physical tactics to gain and maintain power over and control of the abuse target. It is very important to understand that perhaps even the majority of abusers do not utilize physical abuse, ie, you will never be able to find physical injuries, though even non-physical abuse eventually takes its toll upon the emotional and physical health of the person targeted.