noun
corpse of a person who died violently
Refers specifically to a dead body resulting from a violent or unnatural death, such as murder, accident, or disaster. Not used for ordinary deaths.
警察は現場で惨死体を発見した。
The police discovered a corpse of a person who had died violently at the scene.
遺体 is a more formal and respectful term for a dead body, often used in official or funeral contexts, without the violent connotation of 惨死体.
Compound of 惨死 (zanshi, 'violent death') and 体 (tai, 'body'). The exact historical derivation is uncertain, but the meaning is transparent from its components.