A string of characters (letters, numbers, and other symbols) used to authenticate an identity or to verify access authorization.
Sources:
NIST SP 800-12 Rev. 1 under Password from FIPS 140-2

  A protected/private string of letters, numbers, and/or special characters used to authenticate an identity or to authorize access to data.
Sources:
CNSSI 4009-2015 from NSA/CSS Manual Number 3-16 (COMSEC)

  A string of characters (letters, numbers and other symbols) that is used to authenticate an identity, to verify access authorization or to derive cryptographic keys.
Sources:
NIST SP 800-57 Part 2 Rev.1 under Password

  A string of characters (letters, numbers and other symbols) that are used to authenticate an identity, verify access authorization or derive cryptographic keys.
Sources:
NIST SP 800-57 Part 1 Rev. 5 under Password

  A string of characters (letters, numbers, and other symbols) that are used to authenticate an identity or to verify access authorization. A passphrase is a special case of a password that is a sequence of words or other text. In this Recommendation, the use of the term “password” includes this special case.
Sources:
NIST SP 800-133 Rev. 2 under Password

  A string of characters (letters, numbers, and other symbols) used to authenticate an identity or to verify access authorization.
Sources:
NIST SP 800-82r3 from FIPS 140-2

  A type of authenticator consisting of a character string that is intended to be memorized or memorable by the subscriber to permit the claimant to demonstrate something they know as part of an authentication process. Passwords were referred to as memorized secrets in the initial release of SP 800-63B.
Sources:
NIST SP 800-63-4 [