noun, noun which may take the genitive case particle 'no'
unknown fate; missing; not known if alive or dead
Used in news reports, official statements, and formal contexts to describe a person whose survival status is unconfirmed. Often appears as 生死不明の or 生死不明となる.
地震で生死不明の人がまだ数十人いる。
Dozens of people are still missing after the earthquake.
彼
He was missing for a long time after the accident.