Expellimellius is a spell that has been known to moderately burn things.

History

Cho Chang accidentally used it instead of Expelliarmus on Marietta Edgecombe when distracted by Harry Potter, catching her sleeve on fire, which Marietta extinguished easily, though she glared at Harry thereafter.

Etymology

Various etymologies have been suggested, though the exact etymology is unknown; given the context it was probably a mispronunciation of Expelliarmus.

Behind the scenes

• This is almost certainly merely a mispronunciation of Expelliarmus; being distracted by Harry, she said "Expelliarmious" before "Expellimellius" and it is known that when a spell is mispronounced (remember "Wingardliosa") there are ill effects.
• If this is a real spell, it is probably used to burn things, as it does retain the "expel" portion of expelliarmus.

Appearances

• Harry Potter and the Order of the Phoenix (First appearance)