blockade vs obstruction

blockade

noun
  • Any form of formal isolation or inhibition of something, especially with the force of law or arms. 

  • The ships or other forces used to effect a naval blockade. 

  • Inhibition of the activity (function) of chemical messengers or their receptors, such as (often) receptor antagonism. 

  • The physical blocking or surrounding of a place, especially a port, in order to prevent commerce and traffic in or out. 

  • Preventing an opponent's pawn moving by placing a piece in front of it. 

verb
  • To create a blockade against. 

obstruction

noun
  • The act of obstructing, or state of being obstructed. 

  • Something which obstructs or impedes, either intentionally or unintentionally 

  • The condition of having the natural powers obstructed in their usual course; the arrest of the vital functions; death. 

How often have the words blockade and obstruction occurred in a corpus of books? (source: Google Ngram Viewer )