Addiction is a complex phenomenon that can be described in many ways. OBSESSION, with nine letters, is an intense preoccupation with a certain activity or object. DEPENDENCE, with ten letters, is a state of relying on something for support or relief. HABIT, with five letters, is a recurrent, often unconscious pattern of behavior. NEED, with four letters, is a strong feeling of requirement for something. HABITUATION, with eleven letters, is the process of becoming accustomed to something. Habitual, with four letters, is done as a result of long-term repetition. All of these terms are related to addiction and help to explain its complexity.