rowdy-o Share definition Flag Used when something is done in a heartless, careless, angry or rowdy manner. When u tried to chat up that girl she blanked you. Rowdy-o!! That guy carried on rowdy-o in that fight yesterday. rowdy-o by m January 26, 2004 0 0 Get merch Get the rowdy-o mug. Buy Now — $32.95 See more merch