元凶 (げんきょう) Japanese meaning | KotomoraThe police arrested the ringleader of the incident.
Usage patterns
〈事〉の元凶the main cause/culprit behind 〈事〉
He is said to be the root of all evil.
〈事〉の元凶となるto become the main cause of 〈事〉
The factory wastewater became the main cause of the river pollution.
元凶を突き止めるto track down / identify the main culprit or cause
The police tracked down the mastermind behind the incident.