1) Bordered by a ridge 2) Having a wall or rim 
having a raised rim or rampart; ringed
Bordered with an elevation, as a cupped structure; denoting especially certain lingual papillae. ... See: circumvallate. ... Origin: L. Vallo, pp. -atus, to surround with, fr. Vallum, a rampart ... (05 Mar 2000) ... 
(val´āt) having a wall or rim; cup-shaped.
Type: Term Pronunciation: val′āt Definitions: 1. Bordered with an elevation, as a cupped structure; denoting especially certain lingual papillae.
Latin vallatus = walled; hence, the large papillae on the tongue which are depressed below the surface and are surrounded by a groove which is itself bounded by a wall.