the GNU version of the Collaborative International Dictionary of English
n. A box of strong and durable construction, fitted with a lock, used for the purpose of protecting valuable items, such as money or jewelry; a strongbox.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a fireproof metal strongbox (usually in a bank) for storing valuables
Word Usage
"Mocked for repeatedly using the term lockbox to suggest that funding for Social Security and Medicare should be untouchable, Gore was caricatured, not without reason, as a finicky policy wonk."