The activities involving the handling of cryptographic keys and other related security parameters (e.g. passwords) during the entire life cycle of the keys, including their generation, storage, establishment, entry and output, and destruction.
Sources:
CNSSI 4009-2015

  The activities involving the handling of cryptographic keys and other related security parameters (e.g., initialization vectors) during the entire lifecycle of the keys, including their generation, storage, establishment, entry and output, use and destruction.
Sources:
NIST SP 800-12 Rev. 1 under Key Management

  The activities involved in the handling of cryptographic keys and other related parameters (e.g., IVs and domain parameters) during the entire life cycle of the keys, including their generation, storage, establishment, entry and output into cryptographic modules, use and destruction.
Sources:
NIST SP 800-57 Part 2 Rev.1 under Key management

  The activities involving the handling of cryptographic keys and other related security parameters (e.g., IVs and counters) during the entire life cycle of the keys, including their generation, storage, establishment, entry, output, use, and destruction.
Sources:
NIST SP 800-175B Rev. 1 under Key management

  The activities involving the handling of cryptographic keys and other related key information during the entire lifecycle of the keys, including their generation, storage, establishment, entry and output, use, and destruction.
Sources:
NIST SP 800-57 Part 1 Rev. 5 under Key management