Substantial Substantial synonyms significant substantial and significant material substantial and material solid substantial and solid considerable substantial and considerable large substantial and large strong substantial and strong big substantial and big real substantial and real important substantial and important meaningful substantial and meaningful Full list of synonyms (1508) Substantial antonyms minor substantial and minor insubstantial substantial and insubstantial small substantial and small slight substantial and slight insignificant substantial and insignificant inconsiderable substantial and inconsiderable unimportant substantial and unimportant little substantial and little trivial substantial and trivial worthless substantial and worthless Full list of antonyms (108) Share this picture Share this image Share this picture Share this image