English to English

noun (n)

• a secret word or phrase known only to a restricted group(noun.communication)

  Example:
  He forgot the password.
  

  Synonym:
  countersign, parole, watchword, word
  

  source: wordnet30
• A word to be given before a person is allowed to pass; a watchword; a countersign.(noun)

  source: webster1913