Definition of payback

• financial return or reward (especially returns equal to the initial investment)
• the act of taking revenge (harming someone in retaliation for something harmful that they have done) especially in the next life; "Vengeance is mine; I will repay, saith the Lord"--Romans 12:19; "For vengeance I would do nothing. This nation is too great to look for mere revenge"--James Garfield; "he swore vengeance on the man who betrayed him"; "the swiftness of divine retribution"