0 past simple and past participle of flatline
1 to be at a low level and not increase:
Have widescreen TV prices finally flatlined?
They faced the problem of ever-rising operation cost, but flatlined attendance.
Cliff then learns that she had flatlined two nights ago, but was brought back.
Some consider one who has flatlined to be clinically dead, regardless of eventual resuscitation or lack thereof, whereas others insist that one is alive until the moment of brain death.
