quits

The word 'quits' emerged in English during the late 15th century, derived from the Medieval Latin term 'quittus', a variant of 'quietus', meaning "free, clear, discharged from a debt or obligation." This Latin root, 'quietus', itself comes from 'quies', meaning "rest, quiet." The semantic journey is one of release and settlement: from the concept of being at rest, to being legally discharged, and finally to the modern sense of being even after a mutual exchange or repayment. The plural form 'quits' likely developed by analogy with other adjectives ending in '-s' or from its frequent use in reciprocal contexts (e.g., "we are quits").

The word 'quits' is a simplex form. It functions as a predicative adjective in modern English.