Letters that make insubstantial
s, a, b, l, n, t, i, u are letters that make 'insubstantial'
Words within insubstantial
sub, AN, BS, ti, NT, INS, ant, tan, substantial, anti, in, AL, IN, IA, TIA, NSU, Al, In, Ta, Ti are words within 'insubstantial'