Originally the field encompassing both cryptography and cryptanalysis. Today, cryptology in the U.S. Government is the collection and/or exploitation of foreign communications and non- communications emitters, known as SIGINT; and solutions, products, and services, to ensure the availability, integrity, authentication, confidentiality, and non-repudiation of national security telecommunications and information systems, known as IA.
Source(s):
NIST SP 800-59 under Cryptology from Crypto Pub 1-0

  The mathematical science that deals with cryptanalysis and cryptography.
Source(s):
CNSSI 4009-2015

  The science that deals with hidden, disguised, or encrypted communications. It includes communications security and communications intelligence.
Source(s):
NIST SP 800-60 Vol. 1 Rev. 1 under Cryptology
NIST SP 800-60 Vol. 2 Rev. 1 under Cryptology