On the pointy head side there is actually a specific definition and has to do with whether or not you have built in combat recoverability, versus just build to commercial standards and crew it to get from A to B.
There is an entire ANEP on it (ANEP 68), but it's stuck in the NATO review/approval loop so who knows when it will be published, but will give some common performance goals about what that means.
Depending what you have in the CONOPs, you can have a combatant, built to commercial standards, with some additional requirements for how you build things (like shock resistance and redundancy), with enough people to survive some damage.
You can also slap a lot of weapons on a barge and go kamikaze, but that's really just a glass cannon.
AOPS for example has no combat recoverability in the design, and no real threat detection or engagement, but can still do a lot of things like constabulary, HADR and other useful things that don't need that, and MCDVs did a lot like that for decades as well.
The non combatants provide a useful function, but at the same time you don't send a mall security guard into front line combat, so having a mix of both isn't a bad thing.