de Bro·glie (d? broi?), Duc Louis (Victor Pierre Raymond) 1892-1987. French physicist who won a 1929 Nobel Prize for proposing the theory that electrons and other particles exhibit wavelike properties, thus laying the foundation for the field of wave mechanics.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.