noun

• (by extension) Any form of formal isolation or inhibition of something, especially with the force of law or arms.
  "In the mean time, Francesca, separated from Madame de Mercœur, was hidden by a group around the Queen of Sweden. With the wall on one side, and a human blockade on the other, she was left at full leisure to meditate on a vow made at the first announcement of the lottery, namely, that whatever might fall to her lot she would offer in a neighbouring chapel to the Virgin, at whose shrine she would kneel one hour for Guido's safe return."
• (nautical) The ships or other forces used to effect a naval blockade.
• (biology, medicine) Inhibition of the activity (function) of chemical messengers or their receptors, such as (often) receptor antagonism.
  "beta-blockade"
• (chess) The act of preventing an opponent's pawn moving by placing a piece in front of it.

verb

• (transitive) To create a blockade against.
  "On January 5 1969, residents blockaded the level crossing at Newcastleton, ahead of the final passenger train. It was only after the then-local MP David (now Lord) Steel had alighted from the St Pancras-bound Sleeper service and negotiated their dispersal (in return for the release without charge of one of the protest organisers, Reverend Brydon Maben) that the train was allowed on its way."