Source : Webster's Revised Unabridged Dictionary (1913)

Password \Pass"word`\, n.
   A word to be given before a person is allowed to pass; a
   watchword; a countersign. --Macaulay.

Source : WordNet®

password
     n : a secret word or phrase known only to a restricted group;
         "he forgot the password" [syn: {watchword}, {word}, {parole},
          {countersign}]

Source : Free On-Line Dictionary of Computing

password
     
         An arbitrary string of characters chosen by a user
        or {system administrator} and used to authenticate the user
        when he attempts to log on, in order to prevent unauthorised
        access to his account.
     
        A favourite activity among unimaginative {computer nerds} and
        {crackers} is writing programs which attempt to discover
        passwords by using lists of commonly chosen passwords such as
        people's names (spelled forward or backward).  It is
        recommended that to defeat such methods passwords use a
        mixture of upper and lower case letters or digits and avoid
        proper names and real words.  If you have trouble remembering
        random strings of characters, make up an acronym like
        "ihGr8trmP" ("I have great trouble remembering my password").
     
        (1994-10-27)