pellucidity

from WordNet (r) 3.0 (2006)

pellucidity
    n 1: free from obscurity and easy to understand; the
         comprehensibility of clear expression [syn: {clarity},
         {lucidity}, {lucidness}, {pellucidity}, {clearness},
         {limpidity}] [ant: {abstruseness}, {obscureness},
         {obscurity}, {reconditeness}, {unclearness}]
    2: passing light without diffusion or distortion [syn:
       {pellucidness}, {pellucidity}, {limpidity}]

from The Collaborative International Dictionary of English v.0.48

Pellucidity \Pel`lu*cid"i*ty\, Pellucidness \Pel*lu"cid*ness\,
   n. [L. pelluciditas.]
   The quality or state of being pellucid; transparency;
   translucency; clearness; as, the pellucidity of the air.
   --Locke.
   [1913 Webster]