barrier (n.)

  1. a structure or object that impedes free movement

  2. any condition that makes it difficult to make progress or to achieve an objective; intolerance is a barrier to understanding

    [ Syn: roadblock ]

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

The dictionary is based on the WordNet Electronic Lexical Database.
WordNet 3.0 Copyright 2011 by Princeton University. All rights reserved.