barrier (n.)
- abatis
- backstop
- balustrade
- bank
- banquette
- bar
- barbican
- barrage
- barricade
- bastion
- battlement
- block
- blockade
- blockage
- bolt
- boom
- bottleneck
- boundary
- brattice
- breakwater
- breastwork
- buffer
- bulkhead
- bulwark
- bumper
- cecum
- cheval-de-frise
- choking
- clog
- cofferdam
- congestion
- constipation
- curtain
- cushion
- dam
- defense
- diaphragm
- dike
- ditch
- division
- drawbridge
- earthwork
- embankment
- embolism
- embolus
- enclosure
- entanglement
- escarp
- escarpment
- fence
- fender
- fieldwork
- fortification
- frontier
- gate
- gorge
- groin
- ha-ha
- hindrance
- impasse
- impediment
- infarct
- infarction
- jam
- jetty
- levee
- limit
- lock
- logjam
- loophole
- lunette
- machicolation
- mantelet
- mat
- merlon
- midriff
- midsection
- milldam
- moat
- mole
- mound
- obstacle
- obstipation
- obstruction
- outwork
- pad
- padlock
- palisade
- panel
- parapet
- paries
- partition
- portcullis
- rail
- railing
- rampart
- redoubt
- roadblock
- scarp
- sconce
- seawall
- separation
- septum
- stockade
- stop
- stoppage
- strangulation
- wall
- weir
- work
