An obstacle, barrier, or bulwark.
A barrier constructed across a road, especially as a military defence
A place of confrontation.
to close or block a road etc., using a barricade
to keep someone in (or out), using a blockade, especially ships in a port
That which fortifies; especially, a work or works erected to defend a place against attack; a fortified place; a fortress; a fort; a castle.
A jagged pattern sometimes seen during an attack of migraine.
The act of fortifying; the art or science of fortifying places to strengthen defence against an enemy.
An increase in effectiveness, as by adding ingredients.