birth name also birth·name (bûrth?n?m?)n.1. The name given to a person at birth, especially that of an adoptee before he or she is renamed.2. See maiden name.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.