死ななければ

if (someone) doesn't die, unless (someone) dies

→ 死ぬ
死な to die + なければ negative conditional (“if not”)
verb · informal Rare #42,843
if (someone) doesn't die, unless (someone) dies Often used with ならない to express that someone must die.
JA: 死ななければならない。
EN: I have to die.
Conjugation of 死ぬ