Word Forms of "flatline" (6 forms)

Noun

Form	Word
Alternative	flat line
Plural	flatlines

Alternativeflat line

Pluralflatlines

Verb

Form	Word
Participle, Past	flatlined
Participle, Present	flatlining
Past	flatlined
Present, Singular, Third-Person	flatlines

Participle, Pastflatlined

Participle, Presentflatlining

Pastflatlined

Present, Singular, Third-Personflatlines

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.