The Collaborative International Dictionary of English v.0.48:

Obscureness \Ob*scure"ness\, n.
   Obscurity. --Bp. Hall.
   [1913 Webster]

WordNet (r) 3.0 (2006):

obscureness
    n 1: the state of being humble and unimportant [syn:
         humbleness, unimportance, obscureness, lowliness]
    2: the state of being indistinct or indefinite for lack of
       adequate illumination [syn: obscurity, obscureness]
    3: the quality of being unclear or abstruse and hard to
       understand [syn: obscureness, obscurity, abstruseness,
       reconditeness] [ant: clarity, clearness, limpidity,
       lucidity, lucidness, pellucidity]