impalpable
1. [ adjective ] not perceptible to the touch
Examples:

"an impalpable pulse"

Related terms: imperceptible
2. [ adjective ] incapable of being perceived by the senses especially the sense of touch
Synonyms: intangible
Examples:

"the intangible constituent of energy"- James Jeans

Related terms: tangible abstract
3. [ adjective ] imperceptible to the senses or the mind
Examples:

"an impalpable cloud" "impalpable shadows" "impalpable distinctions" "as impalpable as a dream"

Related terms: palpable elusive imperceptible
Similar spelling:   impalpability
  impalement
  implacable