flatline
Word family nounflatletflatnessflattingflattyflatbackflatbedflatboatflatbreadflat capflatcarflatfishflatironflatlandflatlinerflatmateflatpackflat racingflatshareflatwareflatwormadverbflatlingflatlyadjectiveflattedflattishflatwaysflat-chestedflat-footedflatheadflatverbflattenflatline
flat·line /ˈflætlaɪn/ verb be flatlining to be at a low level or standard that is neither increasing nor decreasing 处于低潮 The Tories have been flatlining in the polls. 保守党在民意调查中一直不怎么受欢迎。