Third-person singular simple present indicative form of flatline

An unchanging state, as indicated in a graph of a variable over time. / The disappearance of the rhythmic peaks displayed on a heart monitor.

(intransitive, of the heart) To stop beating. / (intransitive, by extension) To die. / (transitive, slang) To kill. / To stay at the same level, without development; or, to fall.

plural of flatliner

(rare) A patient with no heartbeat.

simple past tense and past participle of flatline

present participle of flatline