"one who looks on at card games and offers unwelcome advice," 1915, from Yiddish, agent noun from kibitz (q.v.). "Der Kibitzer" is noted as the name of a Yiddish humorous weekly published in New York from 1908-1912. ["The Jewish Press in New York City," 1918]
LICENSE TO "KIBITZ"
"This license entitles bearer to 'kibitz'; to sit near any table of players; to criticize, knock, boost or do anything that will abuse players.
"If a man makes a wrong play it is up to the 'kibitzer' to correct him, and the 'kibitzer' will be held personally responsible should the player lose, and this license will be forfeited.
"Any licensed 'kibitzer' not abiding by above rules and regulations Will be subject to fine or imprisonment."
[notice said to have been posed on the bulletin board of the club room of the Associated Traveling Salesmen of New York, quoted in The Clothier and Furnisher, March 1915]