Impalpable, a.
Etymology: [Pref. im- not + palpable: cf. F. impalpable.]
1. Not palpable; that cannot be felt; extremely fine, so that no grit can be perceived by touch. "Impalpable powder." Boyle.
2. Not material; intangible; incorporeal. "Impalpable, void, and bodiless." Holland.
3. Not apprehensible, or readily apprehensible, by the mind; unreal; as, impalpable distinctions.
Shades of meaning
Fernald lists impalpable only as an antonym, under evident.
He lists it without comment; the entries above explain its neighbors.
Synonyms
none given