perviousness

from WordNet (r) 3.0 (2006)

perviousness
    n 1: the quality of being penetrable (by people or light or
         missiles etc.) [syn: {penetrability}, {perviousness}] [ant:
         {impenetrability}, {imperviousness}]

from The Collaborative International Dictionary of English v.0.48

Perviousness \Per"vi*ous*ness\, n.
   The quality or state of being pervious; as, the perviousness
   of glass. --Boyle.
   [1913 Webster]

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