from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Not perceptible to the touch; intangible.
- adj. Difficult to perceive or grasp by the mind.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Not able to be perceived by the senses (especially by touch); intangible or insubstantial
from the GNU version of the Collaborative International Dictionary of English
- adj. Not palpable; that cannot be felt; extremely fine, so that no grit can be perceived by touch.
- adj. Not material; intangible; incorporeal.
- adj. Not apprehensible, or readily apprehensible, by the mind; unreal.
from The Century Dictionary and Cyclopedia
- Incapable of being perceived by touch; wanting palpable substance or consistency; too unsubstantial or too fine to be felt.
- Hence That cannot be grasped by the intellect; incomprehensible; intangible: as, impalpable distinctions.
- Synonyms Imperceptible, intangible, unsubstantial.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. imperceptible to the senses or the mind
- adj. not perceptible to the touch
- adj. incapable of being perceived by the senses especially the sense of touch
From im- + palpable (Wiktionary)