impalpable

1 not capable of being perceived by the sense of touch <the rich colors used in the wall coverings and furniture give the room an impalpable warmth> Synonyms intangibleRelated Words bodiless, immaterial, incorporeal, insubstantial, unsubstantial; ethereal, spiritual, unrealNear Antonyms corporeal, physical; embodied, material, real, solid, substantialAntonyms palpable, tactile, tangible, touchable

2 not perceptible by a sense or by the mind <any difference between the two sound systems is impalpable to all but the most discerning audiophiles> Synonyms imperceptible, inappreciable, indistinguishable, insensibleRelated Words inaudible, intangible, invisible; inconspicuous, indistinct, unnoticeable, unseeable, unseen; faint, insignificant, liminal, slender, slight, subtle, trivial; buried, concealed, covert, disguised, hidden, obscure, shrouded, unapparent, vagueNear Antonyms audible, observable, recognizable, tangible, visible; clear, conspicuous, evident, eye-catching, manifest, noticeable, obvious, plain, prominent, striking; apparent, distinct, significant, straightforwardAntonyms appreciable, discernible (also discernable), palpable, perceptible, ponderable, sensible