adjective 1.not
palpable; incapable of being perceived by the sense of touch; intangible.
2.difficult for the mind to grasp readily or easily: impalpable distinctions.
3.(of powder) so fine that when rubbed between the fingers no grit is felt.
Related forms im·pal·pa·bil·i·ty, noun
im·pal·pa·bly, adverb