A software and/or hardware product that is commercially ready-made and available for sale, lease, or license to the general public.
Sources:
CNSSI 4009-2015
from
NSA/CSS Policy 3-14
Software and hardware that already exists and is available from commercial sources. It is also referred to as off-the-shelf.
Sources:
NISTIR 7622
under Commercial off-the-shelf
Hardware and software IT products that are ready-made and available for purchase by the general public.
Sources:
NISTIR 7711
under Commercial-Off-The-Shelf