Vallum | Webster's Dictionary of the English Language

vallum
vallum, i, n. [collective of 1. vallus; the line of palisades about an intrenchment; hence], an eart...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
vallum
vāllum ī, n vallus, a line of palisades, palisaded rampart, intrenchment, circumvallation : vallo ...

An Elementary Latin Dictionary