The Collaborative International Dictionary of English v.0.48:
Stableness \Sta"ble*ness\, n. The quality or state of being stable, or firmly established; stability. [1913 Webster]WordNet (r) 3.0 (2006):
stableness n 1: the quality or attribute of being firm and steadfast [syn: stability, stableness] [ant: instability, unstableness]