In the Employment Relations Act 2000, a lockout means something an employer does. You might see an employer close their business, stop employing some workers, or break employment agreements. The employer does this to make employees agree to certain work conditions or demands.

When an employer does these things, it is called a lockout if they are trying to force employees to accept certain terms or comply with their demands. You can think of it like the employer is trying to get employees to do something by stopping work or employing people. The employer might also be helping another employer to make their employees agree to something.

If someone takes part in a lockout, it means they are involved in this action, and in the Act, this is referred to as "to lock out".