Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

See What's Trending Now See More Trending Words

flatline

play
verb flat·line \ ˈflat-ˌlīn \

Definition of flatline

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

Explore Merriam-Webster

video-title-words-of-the-year-1066
Words of the Year: 1066
alt-59c52d6ee2f72
Breathing Life Into 'Inspire'
alt-59c448f88ea38
Trending: Kim Jong Un: Trump a 'Dotard'
image1644821030
These Are Fighting Words

Examples of flatline in a Sentence

  1. the patient was fading fast, and doctors expected him to flatline before the night was over

Recent Examples of flatline from the Web

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

flatline Synonyms

Synonyms
check out, conk (out), croak [slang], decease, demise, depart, drop, end, exit, expire, fall, die, go, kick in [slang], kick off [slang], pass (on), pass away, part, peg out [chiefly British], perish, pop off, step out, succumb
Antonyms
breathe, live
Related Words
predecease; consume, disappear, dry up, fade, fail
Near Antonyms
come to, revive; linger; be, exist, subsist; flourish, prosper, thrive

Medical Dictionary

flatline

play
intransitive verb flat·line \ ˈflat-ˌlīn \

medical Definition of flatline

flatlined; flatlining
1 :to register on an electronic monitor as having no heartbeart 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,  May/June 2005
  • 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,  19 Dec. 2007
2 :1die
  • But just because death is expected doesn't mean it's any less depressing when the patient finally flatlines.
  • —Phil Taylor,  Sports Illustrated,  26 Jan. 2009

Learn More about flatline

  1. See words that rhyme with flatline Thesaurus: All synonyms and antonyms for flatline

Seen and Heard

What made you want to look up flatline? Please tell us where you read or heard it (including the quote, if possible).

show hide

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

legerity

play

alert quickness of mind or body

Get Word of the Day daily email!

TRENDING NOW

  1. dotage, dotard a state or period of senile decay

  2. otherwise "in other respects"

  3. federalism Graham says bill gives power to states

  4. bodega "Don’t mess with the beloved bodega."

  5. carceral Of, relating to, or suggesting a jail or prison

SEE ALL

BROWSE DICTIONARY

flatline

Test Your Vocabulary

Merriam-Webster's New Words Quiz—Fall 2017 Edition!

  • young-plant-shoots
  • Which of the following is a new sense of the word bunny?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ
Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words at Play

alt-59c52d6ee2f72
Breathing Life Into 'Inspire'

The word's origins are quite literal

alt-59c4207ecf106
Let's Talk 'Tea'

Spill it, sip it: just make it hot.

image1644821030
8 Words and Phrases from Boxing and Wrestling

Common terms that come from boxing and wrestling

alt-59c2960017c94
The Ambiguity of Pushing 'Up' and 'Back'

When you push a meeting, where does it go?

Ask the Editors

video-title-words-of-the-year-1066
Words of the Year: 1066

Or, Why Pig Meat is Called 'Pork' and Cow Meat is Called 'Beef'

payday
How Often Is 'Biweekly'?

Don't get us started on 'bimonthly'

video-irregardless-grammar-peeve-blend-of-the-synonyms-irrespective-and-regardless
Irregardless

It is in fact a real word (but that doesn't mean you should use it).

video-moose-goose-weird-plurals
Weird Plurals

One goose, two geese. One moose, two... moose. What's up with that?

Word Games

young-plant-shoots
Merriam-Webster's New Words Quiz—Fall 2017 Edition!

You're going to have to memorize the dictionary again.

Take the quiz
stylized-drawing-of-woman-pole-vaulting-across-gap-to-get-trophy
Challenging Vocabulary Quiz Returns!

No tricks, just difficult words.

Take the quiz
How Strong Is Your Vocabulary?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Take the quiz
Word Winder's CrossWinder
Word Winder's CrossWinder

A game of winding words.

Play the game
Examples: flatline in a Sentence