And is entirely a commercial term, not military.
The US did experiment with M-1 Garand carbines, for airborne use, not armoured.
Tanker Enfields, Tanker Garands being sold are commercial versions.
A Destroyer Carbine is a Spanish bolt action 9mm pistol calibre carbine which was used by gendarmerie.
Incidentally, the term "Jungle Carbine" is also something thought up by a business.