addiction
     n 1: being abnormally tolerant to and dependent on something that
          is psychologically or physically habit-forming
          (especially alcohol or narcotic drugs) [syn: {dependence},
           {dependency}, {habituation}]
     2: an abnormally strong craving
     3: (Roman law) a formal award by a court sentence of a thing or
        person to another (as of a debtor to his creditor); a
        surrender to a master; "under Roman law addiction was the
        justification for slavery"
Source: WordNet® 2.0