Mattygrams Share definition Flag a term of endeerment; a nickname given to anyone with the name matt or matthew; the best nickname in the history of nicknames Cara: "I love you mattygrams" Matt: "I love you too" Mattygrams by cara-cakes March 19, 2009 0 0 Get merch Get the Mattygrams mug. Buy Now — $32.95 See more merch