noun
A barrier constructed across a road, especially as a military defence
An obstacle, barrier, or bulwark.
(figuratively, in the plural) A place of confrontation.
(figuratively) Line of people standing behind or closest to the barricade in the pit section of a live music concert.
verb
To close or block a road etc., as, or using, a barricade.
To keep someone in (or out), using a blockade, especially ships in a port.