sub·stan·tial /səb-'stan-chəl/ adj
1 a: of or relating to substance
b: not illusory: having merit
failed to raise a substantial constitutional claim
c: having importance or significance: material
a substantial step had not been taken toward commission of the crime — W. R. LaFave and A. W. Scott, Jr.
2: considerable in quantity: significantly great
would be a substantial abuse of the provisions of this chapter — U.S. Code compare de minimis
sub·stan·ti·al·i·ty /-ˌstan-chē-'a-lə-tē/ n
sub·stan·tial·ly adv
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.