A CA that is signed by a superior CA (e.g., a Root CA or another Intermediate CA) and signs CAs (e.g., another Intermediate or Subordinate CA). The Intermediate CA exists in the middle of a trust chain between the Trust Anchor, or Root, and the subscriber certificate issuing Subordinate CAs.
Source(s):
CNSSI 4009-2015
from
CNSSI 1300
A CA that is subordinate to another CA, and has a CA subordinate to itself.
Source(s):
NIST SP 800-32
under Intermediate CA