PICKET

[noun] [C] - a person or group of people who have a disagreement with their employers, stop work and form a line outside their place of work to try to prevent other people entering their place of work until the problem is solvedThey had people scheduled throughout the day to act as pickets outside the factory gates.The group of men had a sign which said 'Official picket'.A picket can also be the occasion on which this happens. a month-long picketA picket line is a group of workers acting as pickets.Journalists interviewed the union officials on the picket line.The van drivers refused to cross the picket line (= to go past the pickets).