1. 
[syn: groundlessness, idleness]
The Collaborative International Dictionary of English v.0.48:
Groundless \Ground"less\, a. [AS. grundle['a]s bottomless.]
   Without ground or foundation; wanting cause or reason for
   support; not authorized; false; baseless; as, groundless
   fear; a groundless report, rumor, or assertion. --
   Ground"less*ly, adv. -- Ground"less*ness, n.
WordNet (r) 3.0 (2006):
groundlessness
    n 1: the quality of lacking substance or value; "the
         groundlessness of their report was quickly recognized"
         [syn: groundlessness, idleness]