"Quietus" is a word in LAW AND LEGAL, ENGLISH

In old English law. Quit; acquitted; discharged. A word used by the clerk of the pipe, and auditors ln the exchequer, in their acquittances or discharges given to accountants; usuaily concluding with an abinde recessit quietus, (hath gone quit thereof,) which was called a “quietus est" CowelL

Final discharge or acquittance, as from debt or
obligation; that which silences claims; (Fig.) rest; death.