noun (n)

• any authorization to pass or go somewhere(noun.communication)

  Synonym:
  pass
  

  source: wordnet30
• a document issued by a country to a citizen allowing that person to travel abroad and re-enter the home country(noun.communication)

  source: wordnet30
• any quality or characteristic that gains a person a favorable reception or acceptance or admission(noun.attribute)

  Example:
  His wealth was not a passport into the exclusive circles of society.
  

  Synonym:
  recommendation
  

  source: wordnet30
• Permission to pass; a document given by the competent officer of a state, permitting the person therein named to pass or travel from place to place, without molestation, by land or by water.(noun)

  source: webster1913