Real Dictionary

blockade
countable noun: A blockade of a place is an action that is taken to prevent goods or people from entering or leaving it.
verb: If a group of people blockade a place, they stop goods or people from reaching that place. If they blockade a road or a port, they stop people using that road or port.

blockade in American English
a shutting off of a port or region of a belligerent state by the troops or ships of the enemy in order to prevent passage in or out in time of war
noun: the isolating, closing off, or surrounding of a place, as a port, harbor, or city, by hostile ships or troops to prevent entrance or exit
transitive verb: to subject to a blockade

blockade in British English
to impose a blockade on
noun: the interdiction of a nation's sea lines of communications, esp of an individual port by the use of sea power

blockade in the Pharmaceutical Industry
noun: Blockade, or a blockade, is the inhibition of the effect of a hormone, a drug, or a transport system, or the inhibition of the action of a nerve by a drug.