Put the frighteners on somebody British slang
Literally, a frightener is a thug who intimidates victims on behalf of a gang.
To cause one to feel scared by saying something to them so that they will do what you want.
Before the match, my opponent tried to put the frighteners on me.
He remained calm when an armed robber put the frighteners on him.
I didn't want to sign that confession, but the police put the frighteners on me.
To be in serious trouble
1. To meddle with something.
2. To threaten someone.
3. To mock or try to deceive someone.
4. To take part in a dangerous thing or situation.
If you "put the frighteners on someone", you frighten or threaten them.
The verb "put" must be conjugated according to its tense.
The origin of this slang is not clear.