Someone who rarely has anything interesting to say and is generally a bit lacking in substance. A person one would not want to getstuck talking to at a party.
I do hope I'm not seated next to Shaun again; he's such a wetbreakfast.
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).