The Collaborative International Dictionary of English v.0.48:

Intangible \In*tan"gi*ble\, a. [Pref. in- not + tangible: cf. F.
   intangible.]
   Not tangible; incapable of being touched; not perceptible to
   the touch; impalpable; imperceptible. --Bp. Wilkins.
   [1913 Webster]

         A corporation is an artificial, invisible, intangible
         being.                                   --Marshall.
   -- In*tan"gi*ble*ness, n. -- In*tan"gi*bly, adv.
   [1913 Webster]

WordNet (r) 3.0 (2006):

intangibleness
    n 1: the quality of being intangible and not perceptible by
         touch [syn: intangibility, intangibleness,
         impalpability] [ant: palpability, tangibility,
         tangibleness]