mcsinkle Share definition Flag a girl who pees in the sink because her friend is puking in the toilet. Girl 1: "Oh, the toilets being used? I'll just pee in the sink" Girl 2: "You're such a mcsinkle." mcsinkle by Shannon McSinkle September 26, 2009 0 0 Get merch Get the mcsinkle mug. Buy Now — $32.95 See more merch