A Guffy is someone who tends to have a particular interest in nerdy television shows such as Doctor Who or sci-fi films such as Star Wars and Star Trek. Guffy's tend to wear un-ironed and non matching clothing complemented with a pair of thick lense glasses. Someone who owns both an iPhone and iPad and any other hi tech gadgets would be called a Guffy. Guffy's use very posh words and are pedantic about everything.
Someone who likes to read books such as The Lord Of The Rings could also be branded a 'Guffy'.