noun, noun or participle which takes 'suru', intransitive verb
death in agony; agonizing death
Refers to dying while suffering intense physical or mental pain. Often used in literary or dramatic contexts.
彼は事故で悶死した。
He died in agony from the accident.
その小説の主人公は最後に悶死する。
The protagonist of that novel dies an agonizing death at the end.