flatline

verb

flat·​line ˈflat-ˌlīn 

flatlined; flatlining; flatlines

intransitive verb

1

a

: to register on an electronic monitor as having no brain waves or heartbeat

b

: die

2

a

: to be in a state of no progress or advancement

b

: to come to an end

flatliner noun

Synonyms

• check out
• conk (out)
• croak [slang]
• decease
• demise
• depart
• die
• drop
• end
• exit
• expire
• fall
• go
• kick in [slang]
• kick off [slang]
• part
• pass (on)
• pass away
• peg out [chiefly British]
• perish
• pop off
• step out
• succumb

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

The move comes as inflation there moved further above the central bank's 2% target rate, while the British economy is flatlining at best. —CBS News, 19 Dec. 2024

The bad news is that underlying inflation has flatlined, throwing into question what's to come in the new year. —Neil Irwin, Axios, 11 Dec. 2024

Right now, copper is flatlining at around $4.18 a pound, down 18% on a high of $5.10/lb reached seven months ago. —Tim Treadgold, Forbes, 10 Dec. 2024

Overall, the number of college applicants jumped 11% in the 2023-24 school year, even as enrollment flatlined, the latest data from the Common Application found, suggesting more students are applying to the same schools. —Jessica Dickler, CNBC, 15 Oct. 2024

Word History

First Known Use

1980, in the meaning defined at sense 1a

Medical Definition

flatline

intransitive verb

flat·​line ˈflat-ˌlīn 

flatlined; flatlining

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