flatline

plural flatlines · alternative flat line

1. An asystole; the absence of heart contractions or brain waves.
   1. cardiologyThe disappearance of the rhythmic peaks displayed on a heart monitor.
   2. cardiologyThe disappearance of brain waves on an electroencephalogram.

      When brain function ceases, the electroencephalogram shows flatline recordings.

      1972, Louis Lasagna, “Aging and the field of medicine”, in Matilda White Riley, Anne Foner, editors, Aging and Society: Aging and the professions, page 68

2. alsofigurativelyAn unchanging state, as indicated in a graph of a variable over time.

   Thus, you hear words like "flatline recession," "improvement at a greatly reduced rate," "economic hiccup," "recessionette," "rolling readjustment" and "the economy is double clutching."

   1967 June 17, “Business Outlook”, in Business Week, part 6, page 23

3. fishingA line that is run low to the water from the rod tip, generally off a release clip of some type.

present singular third person flatlines · participle present flatlining · participle past flatlined · past flatlined

1. intransitivecardiologyTo stop beating.
2. broadlyintransitivecardiologyTo die.
3. slangtransitiveTo kill.

   If looks could kill, Mona's sharp gaze would have flatlined him in one second.

   2013, Shobha Nihalani, Nine

   1 more example

   After all she'd been through, she needed sleep and food to heal, not endure a lovemaking session that was so passionate that it had pretty much flatlined him as well.

   2017, Stephanie Rowe, Not Quite Dead

4. informalintransitiveTo remain at the same level, without development; or, to fall.

   The economy in Northern Ireland is flatlining and jobs are scarce.

   2012, The Guardian, National Trust attempts to block £100m Giant's Causeway golf course

   1 more example

   But passenger numbers have since recovered to only 85% of pre-March 2020 levels, and growth has flatlined.

   2022 November 16, Mel Holley, “Network News: West Midlands prioritises the return of passsengers”, in RAIL, number 970, page 24

5. To experience significantly decreased rates of change compared to previous rates of change.

   Upon upload, the video got 1,000 views/day for the first week, then flatlined and started getting fewer than ten views/day.

6. intransitivefishingTo fish using a flatline.