Pronunciation: (lok'boks"), [key]
1. a strongbox.
2. a rented post-office box equipped with a lock.
3. Also called lockout box. Television.a closed box, usually fitted with a lock, containing electronic equipment to unscramble cable television pictures for subscribers only: used esp. to prevent children from watching programs with explicit sexual content.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.