Capper
/ˈkæ.pəɹ/
"Capper" in a Sentence (2 examples)
And the capper of it all was, Stacy flew back to Memphis to see me for a day and try to settle our divorce with a one-on-one meeting.
The real capper is when St. John starts fawning over Hugh Hefner, host of the finest Super Bowl party known to man, musing: “The question isn’t whether Hef is the hippest octogenarian on the planet.