noun
flatline
FLAT-lyn
noun
1
A continuous, unbroken line on a monitor showing that a heart or brain has stopped functioning.
"The monitor showed a flatline moments after his heart stopped."
verb
1
To stop functioning entirely, especially the heart; by extension, to stop changing or growing.
"The patient flatlined twice before being stabilized."
"Company profits flatlined after the initial launch surge."
How to Use Flatline
Learner’s notesIn plain EnglishLiterally, a heart or brain monitor going dead flat; figuratively, something that has stopped growing or changing at all.
Common pairings
flatline on the monitor
growth has flatlined
Word Forms
flatlined past tense, flatlines plural, flatlines singular
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Etymology
From "flat" + "line" — describing the straight, unmoving trace an ECG or EEG produces when there's no more activity to record.