P.D.I. Share definition Flag It means that you have a PhD in being really & officially gay ... Just like Adam Sandler got a P.D.I.after that movie ( I Now Pronounce You Chuck and Larry ) P.D.I. by Mr.Small May 22, 2009 0 0 Get merch Get the P.D.I. mug. Buy Now — $32.95 See more merch