Get (one's) own back British phrase informal
To exact vengeance or take reprisals (against someone), especially as a way to equalize some previous mistreatment.
He made nasty comments about me. Now it's time for me to get my own back.
John slandered me, so I got my own back on him by spreading the malicious rumor that he was a conman.
No student dared to criticize the teacher, as they were all afraid she might give them low marks just to get her own back.
To retaliate against someone.
To treat someone badly in the same way they have treated you
To do something disadvantageous or harmful to yourself in order to hurt someone else
To want to avenge
The verb "get" must be conjugated according to its tense.
This phrase dates from the early 1900s.