[syn: innovative, innovational, groundbreaking]
The Collaborative International Dictionary of English v.0.48:
groundbreaking \ground"break`ing\ n.
   The ceremonial breaking of the ground to formally begin a
   construction project. It is sometimes carried out by an
   official who digs the first spadeful of dirt from the ground,
   to begin the preparatory excavation work.
   Syn: groundbreaking ceremony.
        [WordNet 1.5] groundcover
WordNet (r) 3.0 (2006):
groundbreaking
    adj 1: being or producing something like nothing done or
           experienced or created before; "stylistically innovative
           works"; "innovative members of the artistic community";
           "a mind so innovational, so original" [syn: innovative,
           innovational, groundbreaking]
    n 1: the ceremonial breaking of the ground to formally begin a
         construction project [syn: groundbreaking,
         groundbreaking ceremony]