in·substantial \“+\adjective Etymology: probably from French insubstantiel, from Late Latin insubstantialis, from in- in- (I) + substantialis substantial : not substantial: as a.: lacking substance or reality : imaginary, apparitional < an insubstantial mirage floating near the horizon > b.: lacking firmness or solidity of structure : flimsy, frail < delicate insubstantial wrists and ankles > • in·substantiality\“+\noun