The next Harry Potter words to join the dictionary?

Quidditch - the game played by Harry Potter - is now magically appearing in the Oxford Dictionaries, joining that other Potter term "muggle". But what other words dreamed up by author JK Rowling are on the cusp of gaining official recognition? Potterhead... Wrock... Bellatrix... three terms that muggles may not understand. And if you need to be told what a muggle is in the first place, then you can at least consult a dictionary on that one. The BBC has learned that another small list of words associated with the Harry Potter book series are on the Oxford University Press watchlist, which decides on the words likely to gain inclusion in its dictionaries.