Pronunciation: (ground'brā"king), [key]
the act or ceremony of breaking ground for a new construction project.
1. of or pertaining to such a ceremony.
2. originating or pioneering a new endeavor, field of inquiry, or the like: Pasteur's groundbreaking work in bacteriology.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.