A common nickname for the comedian Joey Diaz. He often refers to himself by this name when telling stories from his past where he is a father/mentor figure.
Uncle Joey gave me my first line of coke at 13 and then let a hooker take my virginity.
Short-hand for the word floccinaucinihilipilification, meaning the estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).