jewel boxn. A usually lined box or case for holding jewelry. Also called jewel case.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.jew?el box` n. 1. a small case for jewelry or other valuables. 2. a hinged plastic case for the storage of a compact disc. [1825?35] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.