noun (n)

• the charge for mailing something(noun.possession)

  source: wordnet30
• a small adhesive token stuck on a letter or package to indicate that that postal fees have been paid(noun.communication)

  Synonym:
  postage stamp, stamp
  

  source: wordnet30
• The price established by law to be paid for the conveyance of a letter or other mailable matter by a public post.(noun)

  source: webster1913