weir (n.)
- avenue
- backstop
- bank
- bar
- barrage
- barrier
- blowhole
- boom
- breakwater
- breastwork
- buffer
- bulkhead
- bulwark
- channel
- chute
- cofferdam
- dam
- defense
- dike
- ditch
- door
- earthwork
- egress
- embankment
- escape
- estuary
- exhaust
- exit
- fence
- floodgate
- flume
- gate
- groin
- jam
- jetty
- levee
- lock
- logjam
- loophole
- milldam
- moat
- mole
- mound
- opening
- out
- outcome
- outfall
- outgo
- outlet
- parapet
- penstock
- pore
- port
- portcullis
- rampart
- roadblock
- seawall
- sluice
- spiracle
- spout
- tap
- vent
- venthole
- vomitory
- wall
- work
