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]WordNet (r) 3.0 (2006):
pellucidness n 1: passing light without diffusion or distortion [syn: pellucidness, pellucidity, limpidity]