JWin Share definition Flag Slang for saving money or securing a good deal on a financial transaction. This follows the "FAIL/WIN" meme but is targeted specifically at a financial situation. I saved $10 on lunch today by using a coupon - it was a JWin! JWin by JDiggity2 March 12, 2010 0 0 Get merch Get the JWin mug. Buy Now — $32.95 See more merch