Definition of "dead-bolt" [dead-bolt]

• In a lock, a bolt operated directly by the key. (noun)

The Century Dictionary (Public Domain)

• "There was no chance of someone running outside, since the doors were secured with dead-bolt locks to which Brother Curtis held the key."
• "He added that there were dead-bolt locks that required a key on the inside of all the doors, and bars on the windows."
• "The new video, Inside our labs: Testing door locks, is a rundown of some of the ways we test single-cylinder dead-bolt locks."