noun. A fighting word, sure to impugn a nicknamee's character, face, and bippy.
Real citation: "I was seriously concerned when you mentioned you had a lump on your cock, although as Mildo mentioned that cancerous lumps typically grow on the nutsack. I'm glad it's not a serious lump, but thanks for the scare, jerkbuttface."
(Walid Khouretsoli, Sept. 8, 2005, http://groups.google.com/group/KILROY/msg/a535ccedcfe49292?hl=en&)
Made-up citation: "As Billy Corgan wrote, 'The jerkbuttface in you is the jerkbuttface in me.'"