FOSS, or FOSSA, in anatomy, a kind of cavity in a bone, with a large aperture, but no exit or perforation.
Foss, in fortification, a hollow place, commonly full of water, lying between the scarp and counterscarp, below the rampart; and turning round a fortified place or a post, that is to be defended. See MOAT.
Foss-Way, one of the four principal highways of England, that anciently led through the kingdom, supposed to be made by the Romans, having a ditch upon one side thereof.