1. any person (usually a nerd or geek) who says useless random facts at random times (usually to random people because they have no friends)
2. a poindexter may also use his superior intellect to change a conversation into a lecture
1. poindexter1: did u kno that if each neurone in ur body was spread out, it would stretch 5 billion metres! thats long enuff 2 go around the world 5 times!