obstacle (n.)
- bar
- barrier
- block
- blockade
- blockage
- bottleneck
- catch
- cecum
- check
- choking
- clog
- congestion
- constipation
- cordon
- crimp
- curtain
- determent
- deterrent
- difficulty
- disincentive
- drawback
- embolism
- embolus
- gorge
- hamper
- hang-up
- hazard
- hindrance
- hitch
- hurdle
- impasse
- impediment
- infarct
- infarction
- jam
- joker
- mountain
- objection
- obstipation
- obstruction
- rub
- snag
- stop
- stoppage
- strangulation
