Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun barrier

3 senses of barrier

Sense 1
barrier -- (a structure or object that impedes free movement)
       => obstruction, obstructor, obstructer, impediment, impedimenta -- (any structure that makes progress difficult)

Sense 2
barrier, roadblock -- (any condition that makes it difficult to make progress or to achieve an objective; "intolerance is a barrier to understanding")
       => obstacle, obstruction -- (something immaterial that stands in the way and must be circumvented or surmounted; "lack of imagination is an obstacle to one's advancement"; "the poverty of a district is an obstacle to good education"; "the filibuster was a major obstruction to the success of their plan")

Sense 3
barrier -- (anything serving to maintain separation by obstructing vision or access)
       => mechanism -- (a natural object resembling a machine in structure or function; "the mechanism of the ear"; "the mechanism of infection")