The process of taking a sharp object and using it to cut your own skin. Often used as a way to cope with stress, anger, depression, or loss, though some people have been known to "cut" out of boredom. It has also sometimes been linked to drinking and/or drugs. Two books on the subject are "Cut" by Patricia McCormick, and "Crosses" by Shelly Stoehr.
When you get depressed, you might turn to cutting yourself to releive yourself of emotional pain.