The specific mental state that is necessary to convict someone of particular crimes. mental anguish.N. Extreme distress, anxiety, and any other mental pain that is extreme enough to merit damages for the victim. mental capacity.N. A person's ability to understand what he or she is doing or the effects that other people's actions will have on him or her; see also capacity. mental cruelty. N. In marriage, behavior by one spouse that endangers the mental health of the other or is so humiliating ...