noun (n)

• the physical condition of blocking or filling a passage with an obstruction(noun.state)

  Synonym:
  obstruction
  

  source: wordnet30
• an obstruction in a pipe or tube(noun.artifact)

  Example:
  We had to call a plumber to clear out the blockage in the drainpipe.
  

  Synonym:
  block, closure, occlusion, stop, stoppage
  

  source: wordnet30
• the act of blocking(noun.act)

  Synonym:
  closure, occlusion
  

  source: wordnet30
• The act of blocking up; the state of being blocked up.(noun)

  source: webster1913