From Longman Dictionary of Contemporary Englishget your own back (on somebody)get your own back (on somebody)informalREVENGE to do something bad to someone who has harmed you, as a way of punishing them → revenge She wanted to get her own back on Liz for ruining her party. → own
Examples from the Corpus
get your own back (on somebody)• But you can get your own back.• I've gotta get my own back.• Tupac stoked the feud, claiming to have slept with Biggie Smalls's wife, Smalls threatened to get his own back.• Was that a way of getting his own back?• Women get their own back by borrowing their man's razor.• I hope you haven't gone and done anything silly to it just to get your own back for me going away.• By launching the new forum Mr Heseltine is getting his own back on the now weakened Mr Lamont.• The only way Scott could get his own back was by replacing my voice during the post-production. 