noun

• (uncountable, countable) The state or condition of being blocked.
  "Only when one has seen a Control Office at first-hand does one realise the vast amount of unsparing but largely unsung work that is behind the eventual publication, perhaps, of a paragraph in this journal's "Motive Power Miscellany" recording the appearance, within hours of the complete blockage of a main line, of many of its trains, passenger and freight, on routes quite foreign to them; and of effective emergency services either side of the disaster area."
• (countable) The thing that is the cause of such a state, blocking a passage.
  "There was a blockage in the sewer, so we called out the plumber."
• (biology, medicine) Occlusion of a lumen (especially that of a blood vessel or intestine), or the thing that is causing it; as:
  "Blockage of circulation quickly leads to ischemia."
• (biology, medicine) Occlusion of a lumen (especially that of a blood vessel or intestine), or the thing that is causing it; as: