adj. 1 a of real importance or value (made a substantial contribution). b of large size or amount (awarded substantial damages). 2 of solid material or structure; stout (a man of substantial build; a substantial house). 3 commercially successful; wealthy. 4 essential; true in large part (substantial truth). 5 having substance; real. substantiality n. substantially adv.
[ ME f. OF substantiel or LL substantialis (as SUBSTANCE) ]