substantial in WordNet English dictionary

1. providing abundant nourishment
   "a hearty meal"; "good solid food"; "ate a substantial breakfast"; "four square meals a day"
   hearty  satisfying  solid  square  substantial 
   
2. having substance or capable of being treated as fact; not imaginary
   "the substantial world"; "a mere dream, neither substantial nor practical"; "most ponderous and substantial things"- Shakespeare
   substantial  real  material 
   
3. fairly large
   "won by a substantial margin"
   significant  substantial 
   
4. of good quality and condition; solidly built
   "a solid foundation"; "several substantial timber buildings"
   solid  strong  substantial 
   
5. having a firm basis in reality and being therefore important, meaningful, or considerable
   "substantial equivalents"
   substantial  substantive