A type of person found on guitar threads, who lectures any "noob" (new person) trying to find out basic guitar info such as: "what type of effects does Slash use?" the noob is repremanded and/or mocked for their choice of music and the need to ask such questions. The Thread Geek invariably goes off topic talking absolute bullshit about extravagant effects pedals, Rare or (badly) modded ugly guitars, pointless exotic scales and dissing really popular bands (usually Heavy Metal bands eg. Megadeth), by claiming some obscure guitar player (Usually Steve Vai) is technically better and its a shame how tasteless the masses are.
Noob: "Hey does anybody know what kind of effects Slash uses?"
Guitar Thread Geek: "tisk tisk, Slash is so overrated and sloppy, I mean if you have to ask that you shouldn't be playing guitar, I'd recommend you check out Steve Vai and his amazing solo played through the mixalodian scale with a bagpipe emulator on his rotten floor board 13 string custom guitar, I personally like to use the entire range of pedals run through a super mega boogie woogie J-899999 amp that really gives an exsquisite sound with a cross patched fade in and scream out pad."
Noob: "WTF??? Fuck you douche, I just wanted some advice"