noun (n)

• being abnormally tolerant to and dependent on something that is psychologically or physically habit-forming (especially alcohol or narcotic drugs)(noun.state)

  Synonym:
  dependance, dependence, dependency, habituation
  

  source: wordnet30
• an abnormally strong craving(noun.feeling)

  source: wordnet30
• (Roman law) a formal award by a magistrate of a thing or person to another person (as the award of a debtor to his creditor); a surrender to a master(noun.act)

  Example:
  Under Roman law addiction was the justification for slavery.
  

  source: wordnet30
• The state of being addicted; devotion; inclination.(noun)

  source: webster1913