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intr.v. flat·lined, flat·lin·ing, flat·lines
1. To show a horizontal line on the monitor of an electrocardiogram or an electroencephalogram, indicating no electrical activity.
2. Informal To die.
3. To be in an unchanging condition: Participation in civic activities has flatlined in recent years.
Being or relating to an electrocardiogram or an electroencephalogram that indicates no electrical activity.
1. (Medicine) to die or be so near death that the display of one's vital signs on medical monitoring equipment shows a flat line rather than peaks and troughs
2. to remain at a continuous low level