- a strongbox.
- a rented post-office box equipped with a lock.
- 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 especially to prevent children from watching programs with explicit sexual content.
Origin of lockbox
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018