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

    Synonyms : roadblock
    Type Of : obstruction, obstacle
    Examples :
    • intolerance is a barrier to understanding
  2. anything serving to maintain separation by obstructing vision or access

    Type Of : mechanism
  3. a structure or object that impedes free movement

    Type Of : obstructor, obstructer, impediment, impedimenta, obstruction