postmortem stiffening of the limbs of a corpse
via PubMed
Rigor mortis (from Latin rigor 'stiffness' and mortis 'of death'), or postmortem rigidity, is the fourth stage of death. It is one of the recognizable signs of death, characterized by stiffening of the limbs of the corpse caused by chemical changes in the muscles postmortem (mainly calcium). In humans, rigor mortis can occur as soon as four hours after death.
Physiology
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).