adj. 25B6; adjective
an insubstantial structure : FLIMSY, slight, fragile, breakable, weak, frail, unstable, shaky, wobbly, rickety, ramshackle, jerry-built.
insubstantial evidence : WEAK, flimsy, feeble, poor, inadequate, insufficient, tenuous, insignificant, inconsequential, unsubstantial, unconvincing, implausible, unsatisfactory, paltry.
the light made her seem insubstantial : INTANGIBLE, impalpable, untouchable, discarnate, unsubstantial, incorporeal; imaginary, unreal, illusory, spectral, ghostlike, vaporous; Philosophy immaterial.
sturdy, sound, tangible.