L4 Protrusion Share definition Flag Refers to a woman's engagement/wedding ring. Especially useful in a bar/social setting. "She's hot, but she has a giant L4 protrusion." L4 Protrusion by mustangmom August 20, 2013 0 0 Get merch Get the L4 Protrusion mug. Buy Now — $32.95 See more merch
