flat·​line | \ ˈflat-ˌlīn How to pronounce flatline (audio) \
flatlined; flatlining; flatlines

Definition of flatline

intransitive verb

1a : to register on an electronic monitor as having no brain waves or heartbeat
b : die
2a : to be in a state of no progress or advancement
b : to come to an end

Other Words from flatline

flatliner noun

Synonyms & Antonyms for flatline



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Examples of flatline in a Sentence

the patient was fading fast, and doctors expected him to flatline before the night was over
Recent Examples on the Web With no further policy, the country’s emissions are projected to flatline or modestly fall from that level. Robinson Meyer, The Atlantic, 15 June 2022 Democrats couldn’t have predicted many of the crises that have caused the Biden presidency to flatline since late August of last year. Alex Shephard, The New Republic, 14 June 2022 Indeed, Zandi is predicting the year-over-year rate of home price growth will flatline to 0% by this time next year. Fortune, 13 June 2022 Typically, markets flatline ahead of such consequential Fed meetings as investors hang on the sidelines until news breaks on Fed policy matters. Bernhard Warner, Fortune, 26 Jan. 2022 The decline of oil investment goes against predictions the IEA made just last year in the same report, which forecasted global oil demand to flatline rather than peak in the next two decades, settling at 104.1 million barrels per day by 2040. Sophie Mellor, Fortune, 13 Oct. 2021 Bank of America, for one, is now predicting stocks will largely flatline through next year. Anne Sraders, Fortune, 8 Sep. 2021 House Budget Chairman John Yarmuth, D-Ky., has suggested Democrats might flatline defense instead of providing the small increase Biden requested, potentially distributing an extra $12 billion to nondefense programs. al, 14 June 2021 In December, with the pandemic surging, many economists figured GDP would flatline or even dip early in the year. Paul Davidson, USA TODAY, 23 Feb. 2021 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'flatline.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of flatline

1980, in the meaning defined at sense 1a

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The first known use of flatline was in 1980

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Last Updated

23 Jun 2022

Cite this Entry

“Flatline.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/flatline. Accessed 3 Jul. 2022.

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More Definitions for flatline


intransitive verb
flat·​line | \ ˈflat-ˌlīn How to pronounce flatline (audio) \
flatlined; flatlining

Medical Definition of flatline

1 : to register on an electronic monitor as having no heartbeat or brain waves : to experience cessation of heart contractions or brain wave activity as indicated by a flat line on a electrocardiogram or electroencephalogram I flatlined on the operating table, but Dr. Bunsom managed to revive me.— Alison Wright, Yoga Journal He used to be ill quite a bit as a younger child, and his heart flatlined four times before he was 6.— Ginnie Graham, Tulsa World
2 : die entry 1 But just because death is expected doesn't mean it's any less depressing when the patient finally flatlines.— Phil Taylor, Sports Illustrated


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