WordWeb Online

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

See also: considerable, essential, material, solidness, sound, substantiality, substantialness, wholesome

Antonym: insubstantial

Encyclopedia: Substantial