Synonyms barrier (a bar, wall, fence or gate that stops people or vehicles from entering a place): The cottage was surrounded by an old wooden fence.
barricade (a temporary structure placed across a road, path, etc. to prevent people from getting through): After all police erected a barricade across the road.
railings (a fence or barrier made from metal bars): He then chained his motorcycle to the park railings.
obstacle (something that blocks your path): The obstacle in our way this time was a tree trunk in the road.
roadblock (a barricade put across a road to stop traffic): The army also set up roadblocks to check passing vehicles.
hurdle (a barrier for jumping over in a race): The horse fell while it was jumping the first hurdle.