" impalpable "

1: not capable of being perceived by the sense of touch;

  * e.g., " ... the rich colors used in the wall coverings and furniture give the room an impalpable warmth "

•  Synonyms : 

•  intangible

•  Antonyms : 

•  palpable,

•  tactile,

•  tangible,

•  touchable

2: not perceptible by a sense or by the mind;

  * e.g., " ... any difference between the two sound systems is impalpable to all but the most discerning audiophiles "

•  Synonyms : 

•  imperceptible,

•  inappreciable,

•  indistinguishable,

•  insensible

•  Antonyms : 

•  appreciable,

•  discernible,

•  palpable,

•  perceptible,

•  ponderable,

•  sensible