an affectionate term for any addiction, especially a gambling addiction where the person gambles away their money playing, specifically blackjack and poker
(N.B. jack blacker is actually an amalgamation of the games of blackjack and poker)
son: Dad, what is a jack blacker
Dad: son, it's when people are addicted to card games where you need to bet money, especially blackjack and poker. it becomes a disease that needs to be treated ASAP in that particular individual. Otherwise, people can lose their financial savings, their marriages, their property and the like. some even end up doing harakiri.