Pronounced kwahy-ee-tu s.
The definition for Quietus was found on Dictionary.com.
It is a noun with three definitions. The first definition describes the word as meaning a finishing stroke, or something which can effectively end something.
Definition two is a discharge, or a release from life. According to a secondary source quietus is death, or something that causes it.
And finally, definition three is a period of retirement or inactivity.
Will I add this word to my vocabulary? Oh yes!