INSUBSTANTIAL Meaning of INSUBSTANTIAL in English insubstantial BrE AmE ˌɪn səb ˈstæn t ʃ ə l ◂ § \ -sʌb-, -ˈstɑːn t ʃ- ▷ insubstantial|ly i Longman Pronunciation English Dictionary. Английский словарь произношений Longman. 2012