yanguage Share definition Flag A dialect of the English language where the letter "L" is almost always replaced with "Y," among other replacements. The result is talking like a baby, more or less. "Yights, Yemonade, and Yivee""Seriously, quit it with the yanguage" yanguage by tlap July 19, 2012 0 0 Get merch Get the yanguage mug. Buy Now — $32.95 See more merch