A lot vs. Alot: 9 Grammatical Pitfalls
late 12c., from Anglo-French curuner, from Latin custos placitorum coronae, originally the title of the officer with the duty of protecting the property of the royal family, from Latin corona, literally "crown" (see crown (n.)). The duties of the office gradually narrowed and by 17c. the chief function was to determine the cause of death in cases not obviously natural.
coroner cor·o·ner (kôr'ə-nər)
A public officer whose primary function is to investigate by inquest any death thought to be of other than natural causes.