quits
adj.adj. on equal terms with someone because you have paid back a debt or finished a disagreement. You use this when you no longer owe someone anything.
adj. on even terms with another person, typically after the settlement of a debt or the completion of a reciprocal action. Used predicatively after a linking verb.
I'll pay for lunch today and then we're quits.
After he returned the favor by helping me move house, I told him we were finally quits.
The two rivals shook hands after the final match, agreeing that their long-standing series of victories and defeats had left them quits at last.
See the etymology of the corresponding lemma form.
Used predicatively, typically following the verb 'to be'. Often appears in the phrase 'to call it quits', meaning to stop an activity.
we are quitwe are quitsIn the sense of being even or on equal terms, the word must be plural 'quits' rather than the verb 'quit'.