noun
person who died an unnatural death; person accidentally killed
Refers to a person whose death was not due to natural causes, such as an accident, suicide, or crime. Often used in news reports or official contexts.
火災現場から変死者が発見された。
A person who died an unnatural death was found at the fire scene.
警察は変死者の身元を確認している。
The police are identifying the person who died an unnatural death.
変死 is the noun for 'unnatural death' itself, whereas 変死者 refers to the person who died such a death.
Compound of 変 (へん, 'strange, unusual') and 死者 (ししゃ, 'deceased person'). The exact historical derivation is uncertain, but the term is straightforwardly understood as 'person who died an unusual death'.