impalpable

I adjective attenuated, barely seen, concealed, covered, covert, delicate, difficult to feel, difficult to perceive, difficult to see, doubtable, dubitable, equivocal, fine, hidden, immateriate, imperceptible, inappreciable, inapprehensible, incapable of being perceived, inconspicuous, incorporeal, indefinite, indistinct, infinitesimal, intangible, invisible, little, microscopic, minute, nonmaterial, not manifest, not readily discerned, obscure, quod tangi non potest, screened, shaded, shadowy, shrouded, slight, small, subtle, tiny, unapparent, unclear, undiscernable, unevident, unexplicit, unnoticeable, unobservable, unobvious, unpatent, unperceivable, unplain, unpronounced, unreal, unrecognizable, unrevealed, unsubstantial, untouchable, vague, veiled, very fine II index elusive, imponderable, inappreciable, incorporeal, indiscernible, insubstantial, intangible, minimal, obscure (abstruse), obscure (faint), vague