poncho legs Share definition Flag Quite self explanatory. A person with large flabby discolored legs, mistaken as a tool or device to keep something dry. "Hey look at that ladies poncho legs." "Ew, They are just hanging over the bicycle seat." poncho legs by The Incorrectum January 31, 2010 0 0 Get merch Get the poncho legs mug. Buy Now — $32.95 See more merch