Mud Flaps Share definition Flag noun. From the latin phrase mudicus flappinus; when a female gets feces caked on her floppy meat wings after several bouts of alternating anal, followed by vaginal, intercourse. She had some serious mud flaps after our two stroke piston pump. Mud Flaps by Trucker09 June 10, 2010 0 0 Get merch Get the Mud Flaps mug. Buy Now — $32.95 See more merch