(in ancient Rome) a defensive wall, rampart, or stockade.
- ‘There was a ditch on the north side, and a military zone on the south defined by an earthwork called the vallum.’
- ‘The final addition was the ‘vallum’ to the rear of the wall.’
- ‘A vallum some 27 feet wide and nine feet deep was dug as further protection for the wall.’
Latin, collective from vallus stake, palisade.