n. [ Cf. It. bloccata. See Block, v. t. ] 1. The shutting up of a place by troops or ships, with the purpose of preventing ingress or egress, or the reception of supplies; as, the blockade of the ports of an enemy. [ 1913 Webster ]

☞ Blockade is now usually applied to an investment with ships or vessels, while siege is used of an investment by land forces. To constitute a blockade, the investing power must be able to apply its force to every point of practicable access, so as to render it dangerous to attempt to enter; and there is no blockade of that port where its force can not be brought to bear. Kent. [ 1913 Webster ]

2. An obstruction to passage. [ 1913 Webster ]

3. (physiology) interference with transmission of a physiological signal, or a physiological reaction. [ PJC ]

To raise a blockade. See under Raise. [ 1913 Webster ]

v. t. [ imp. & p. p. Blockaded; p. pr. & vb. n. Blockading. ] 1. To shut up, as a town or fortress, by investing it with troops or vessels or war for the purpose of preventing ingress or egress, or the introduction of supplies. See note under Blockade, n. “Blockaded the place by sea.” Gilpin. [ 1913 Webster ]

2. Hence, to shut in so as to prevent egress. [ 1913 Webster ]

Till storm and driving ice blockade him there. Wordsworth. [ 1913 Webster ]

3. To obstruct entrance to or egress from. [ 1913 Webster ]

Huge bales of British cloth blockade the door. Pope. [ 1913 Webster ]

adj. having access obstructed by emplacement of a barrier, or by threat of force.
Syn. -- barricaded, barred. [ WordNet 1.5 ]

n. 1. One who blockades. [ 1913 Webster ]

2. (Naut.) A vessel employed in blockading. [ 1913 Webster ]