1
general::
1. Keep out, prevent from entering. For example, Karen was so angry at her brother that she locked him out of the house. [Late 1500s] Shakespeare had it in The Comedy of Errors (4:1): "For locking me out of my doors by day." 2. Withhold work from employees during a labor dispute, as in The company threatened to lock out the strikers permanently. [Mid-1800s]
American Heritage Idioms