From The Collaborative International Dictionary of English v.0.48:
Quietus \Qui*e"tus\, n. [LL. quietus quit, discharged, L., at rest, quiet, dead. See Quiet, a., and cf. Quit, a.] Final discharge or acquittance, as from debt or obligation; that which silences claims; (Fig.) rest; death. [1913 Webster]
When he himself might his quietus make With a bare bodkin. --Shak. [1913 Webster]