Source : Webster's Revised Unabridged Dictionary (1913)

Immateriality \Im`ma*te`ri*al"i*ty\, n.; pl. {Immaterialities}.
   [Cf. F. immat['e]rialit['e].]
   The state or quality of being immaterial or incorporeal; as,
   the immateriality of the soul.

Source : WordNet®

immateriality
     n 1: complete irrelevance requiring no further consideration
          [ant: {materiality}]
     2: the quality of not being physical; not consisting of matter
        [syn: {incorporeality}] [ant: {materiality}, {materiality}]