taurobolium
The ritual slaughter of a bull.
historical
The cult of the Magna Mater, borrowing the civic spirit proper to Roman religion, made of the official taurobolium a manifestation of loyalty to the institutions of the Roman Empire.
Where it comes from
Borrowed from Latin taurobolium, from Ancient Greek ταυροβόλιον (taurobólion).
Adapted from the Wiktionary entry taurobolium (CC BY-SA 4.0).