A term one uses whenever someone makes up a word. Simply insert their name in front of the -ism and viola! Also works if the word is just two words meshed together in a way that doesn't make up any actual word that can be found in the dictionary.
Gordon: "I was just talking to that guy over there. He was a real shufflemess."
Jeff: "... Shufflemess? ... Hehehe... It's a Gordon-ism." (aka, a *name*-ism)