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impalpability

adjective

not palpable; incapable of being perceived by the sense of touch; intangible.
difficult for the mind to grasp readily or easily: impalpable distinctions.
(of powder) so fine that when rubbed between the fingers no grit is felt.

adjective

imperceptible, esp to the touchimpalpable shadows
difficult to understand; abstruse

adj.

c.1500, from French impalpable, from Medieval Latin impalpabilis, from assimilated form of in- “not, opposite of” (see in- (1)) + palpabilis (see palpable). Figurative use from 1774. Related: Impalpably; impalpability.