the money or advantage you gain from a business, project, or something you have done:
The immediate payback for them is publicity.
2 [uncountable] American English informal
when you do something to make someone suffer because of something they have done to harm you [↪ revenge]:
I guess it's payback time.
the period of time in which you will make a profit on an investment
the period of time over which you must pay back money you have borrowed