The Collaborative International Dictionary of English v.0.48:
Impalpability \Im*pal`pa*bil"i*ty\, n. [Cf. F. impalpabilit['e].] The quality of being impalpable. --Jortin. [1913 Webster]WordNet (r) 3.0 (2006):
impalpability n 1: the quality of being intangible and not perceptible by touch [syn: intangibility, intangibleness, impalpability] [ant: palpability, tangibility, tangibleness]