Synonyms for Intangible (same or very similar meaning)
WordNet sense 1 (assets that are saleable though not material or physical):
intangible asset
WordNet sense 2 (incapable of being perceived by the senses especially the sense of touch):
impalpable
WordNet sense 3 (impossible to identify):
unidentifiable
WordNet sense 4 (lacking substance or reality; incapable of being touched or seen):
nonphysical
WordNet sense 5 (not consisting of matter):
nonmaterial
From the ODE community, based on WordNet
add/edit