• WordNet 3.6
    • adj impalpable imperceptible to the senses or the mind "an impalpable cloud","impalpable shadows","impalpable distinctions","as impalpable as a dream"
    • adj impalpable not perceptible to the touch "an impalpable pulse"
    • adj impalpable incapable of being perceived by the senses especially the sense of touch "the intangible constituent of energy"- James Jeans"
    • ***
Webster's Revised Unabridged Dictionary
    • Impalpable Not apprehensible, or readily apprehensible, by the mind; unreal; as, impalpable distinctions.
    • Impalpable Not material; intangible; incorporeal. "Impalpable , void, and bodiless."
    • Impalpable Not palpable; that cannot be felt; extremely fine, so that no grit can be perceived by touch. "Impalpable powder."
    • ***
Century Dictionary and Cyclopedia
    • impalpable Incapable of being perceived by touch; wanting palpable substance or consistency; too unsubstantial or too fine to be felt. In chemical analysis a fragment of a rock or mineral is often required to be ground or pulverized to so fine a powder that when it is rubbed between the fiugers no grit is perceptible. This is called reducing to an impalpable powder.
    • impalpable Hence That cannot be grasped by the intellect; incomprehensible; intangible: as, impalpable distinctions.
    • impalpable Synonyms Imperceptible, intangible, unsubstantial.
    • ***
Chambers's Twentieth Century Dictionary
    • adj Impalpable im-pal′pa-bl not perceivable by touch: not coarse: not easily understood
    • ***


  • W. Stanley Jevons
    W. Stanley Jevons
    “Value is the most invincible and impalpable of ghosts, and comes and goes unthought of while the visible and dense matter remains as it was.”


Webster's Revised Unabridged Dictionary
Pref. im-, not + palpable,: cf. F. impalpable,


In literature:

He feels a bleak and impalpable alienation from those who are all the world to him.
"Old Junk" by H. M. Tomlinson
It is impossible to make marble imitate that which is impalpable.
"The Greville Memoirs" by Charles C. F. Greville
It was strange that a thing so impalpable as gossip should influence so strong a man as John Gourlay to his ruin.
"The House with the Green Shutters" by George Douglas Brown
She felt, as she spoke those words, the silent, still, impalpable recoil in her companion's heart.
"A Beautiful Alien" by Julia Magruder
Take one ounce white lead; half ounce gum arabic, in the impalpable powder; half ounce white rosin, in the fine powder.
"The Ladies Book of Useful Information" by Anonymous
Each fought the obsession in his own way, but it is hard to fight the impalpable, hence their sick fancies grew in spite of themselves.
"The Boy Scouts Book of Campfire Stories" by Various
But I chafed at the impalpable barrier which was always between us.
"The Crack of Doom" by Robert Cromie
Her conversation, so charmingly impalpable, solidifies into discussion.
"Modern Women and What is Said of Them" by Anonymous
Something dropped upon his face like a light, impalpable shower.
"The Dead Command" by Vicente Blasco Ibáñez
The vague, impalpable things in his mind, cloudy emotions half shaped towards ideas, vanished before the rough grasp of words.
"Tales of Space and Time" by Herbert George Wells

In poetry:

Thou hast vanished from my reach
leaving an impalpable touch in the blue of the sky,
an invisible image in the wind moving
among the shadows.
"Fireflies" by Rabindranath Tagore
We meet them at the doorway, on the stair,
Along the passages they come and go,
Impalpable impressions on the air,
A sense of something moving to and fro.
"Haunted Houses. (Birds Of Passage. Flight The First)" by Henry Wadsworth Longfellow
He also, whom
The load of double empire, half the world
His own, within a living tomb
Press'd down at Yuste,--Spain's great banner furl'd
His winding-sheet around him,--while he strove
The impalpable Above
"At Hursley In Marden" by Francis Turner Palgrave
Ten paces round me solid earth stretches,
Moving as I move through impalpable regions
Of space unbounded, unreal, untenanted,
Or tenanted, if tenanted, by powerless anatomies,
Unbreathing hosts, phantom legjons.
"Fog" by George Rostrevor Hamilton
Buoyant, impalpable, relentless, thin,
Rise the clear, mocking walls. I strive in vain
To reach the pulsing heart that beats within,
Or with persistence of a cold disdain,
To quell the gladness which I may not win.
"Gulf-Stream" by Susan Coolidge
The falcon mother cannot will her hand
Up to the bed, nor break the manacle
His exile sets upon her harsh command
That he should say the time is beautiful-
Transfigured by her own possessing light:
The sick man craves the impalpable night.
"Mother And Son" by Allen Tate