flat·lineBrE/ˈflætlaɪn/NAmE/ˈflætlaɪn/verbpresent simple - I / you / we / theyflatlineBrE/ˈflætlaɪn/NAmE/ˈflætlaɪn/present simple - he / she / itflatlinesBrE/ˈflætlaɪnz/NAmE/ˈflætlaɪnz/past simpleflatlinedBrE/ˈflætlaɪnd/NAmE/ˈflætlaɪnd/past participleflatlinedBrE/ˈflætlaɪnd/NAmE/ˈflætlaɪnd/ -ing formflatliningBrE/ˈflætlaɪnɪŋ/NAmE/ˈflætlaɪnɪŋ/ (informal) [I]todie死;断气[I]tobeatalowlevelandfailtoimproveorincrease处于低潮;没有起色