capper

noun6

1. •
   A device or person that applies caps, as to bullets or bottles.
2. •
   A finale; something that is conclusively better, or "caps it all off".

   • 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. — 2008
3. •
   (Internet) A person who records a television broadcast or video stream to their computer.
4. •
   A person that makes or sells caps.
5. •
   (slang) A person who caps i.e. is inclined to untruth, a fibber.
6. •
   (slang, old-fashioned) A by-bidder; a decoy for gamblers.