Noun

1. Agent noun of kibitz; a person who offers unsolicited views, advice, or criticism; one who kibitzes.

   Did I ask you what you thought about my card hand, you kibitzer!

   • 1971, John Updike, New York Times review on 'Rabbit Redux', 05/11/71, http://www.nytimes.com/1971/11/05/books/updike-rabbit.html,

     Neither good nor evil exactly, he is the ultimate catalyst or kibitzer, a blue-note howl of pain and laughter such as Charlie Parker might have blown.