adjective.
Surrounded with a wall; enclosed with a rampart.
adjective.
Surrounded by a ridge or elevation.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
verb.
surround with or as if with a rampart or other fortification
Word Usage
"Towards the root of the tongue is another kind of papillæ, the circumvallate, eight to fifteen in number, arranged in the form of the letter V, with the apex directed backwards."