Lewis Short
con-vallo, āvi, ātum, 1
* V. a.; lit., to surround with an intrenchment; hence, in gen., to surround, encircle (late Lat.): terras omnes Oceani ambitu,Gell. 12, 13, 20. —Trop., Tert. Carm. de Judicio Dom. 6.
Charlton T. Lewis, Charles Short, A Latin Dictionary