Final answer:
A lockout is a technique used by employers to break a union by denying workers access to the property and cutting off their pay.
Step-by-step explanation:
In the context of breaking a union, the technique described in the question is known as a lockout. A lockout occurs when a company refuses to allow workers onto its property and stops paying them in order to put pressure on the union and gain leverage in negotiations. This tactic was commonly used by employers to weaken unions and force workers to accept unfavorable conditions or terms.
For example, in the Homestead Strike of 1892, Andrew Carnegie's Homestead Steel Mill locked out union workers who were demanding better wages and working conditions. The company walled off the factory, hired private guards, and brought in strikebreakers to keep the factory operating.
In summary, a lockout is a technique used by employers to break a union by denying workers access to the property and cutting off their pay.