Step 1: Define the term.
A lockout is when the management or owner of a factory or workplace temporarily shuts it down and refuses to let workers in, usually during a dispute over wages, conditions, or demands raised by the workers.
Step 2: Give the purpose.
It is used by employers as a bargaining tool against workers, the way a strike is used by workers against employers, since it puts pressure on employees by stopping their work and pay.
Final Answer:
A lockout is the employer's closing of a workplace to pressure workers during an industrial dispute.