substantial

adjective | \ səb-ˈstan-chəl \ | sub·stan·tial

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 identification of serious and substantial failure to perform —U.S. Code — compare de minimis