Learn how to say Truncheon correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word truncheon:
a short, thick stick carried as a weapon by a police officer.
a staff or baton acting as a symbol of authority, especially that used by the Earl Marshal.
Middle English (denoting a piece broken off (especially from a spear), also a cudgel): from Old French tronchon ‘stump’, based on Latin truncus ‘trunk’
Remember that truncheon ends with -eon.