1. (noun) any condition that makes it difficult to make progress or to achieve an objective

• roadblock

1. (noun) a structure or object that impedes free movement

• balusters
• balustrade
• banister
• bannister
• handrail
• barricade
• barricade
• roadblock
• breakwater
• bulwark
• groin
• groyne
• jetty
• mole
• seawall
• bulwark
• crash barrier
• dam
• dike
• dyke
• fence
• fencing
• fender
• wing
• grate
• grating
• hurdle
• movable barrier
• rail
• railing
• revetment
• starting gate
• starting stall

2. (noun) any condition that makes it difficult to make progress or to achieve an objective

• ideological barrier
• language barrier

3. (noun) anything serving to maintain separation by obstructing vision or access

• bar
• blood-brain barrier
• curtain

1. (noun) a structure or object that impedes free movement

• impediment
• impedimenta
• obstructer
• obstruction
• obstructor

2. (noun) any condition that makes it difficult to make progress or to achieve an objective

• obstacle
• obstruction

3. (noun) anything serving to maintain separation by obstructing vision or access

• mechanism