Avada Kedavra (Killing Curse)

Type: Curse

Pronunciation: ah-VAH-dah keh-DAV-rah

Description: Causes instantaneous death. It is accompanied by a flash of green light and a rushing noise. There is no known counter-curse that can protect the victim from dying, except for a loving sacrifice. It is one of the three Unforgivable Curses.
Harry Potter was saved from this spell a number of times, both by his mother's sacrifice, because he was an accidental horcrux, and because his wand and his enemy's were made of the same core.

Seen/Mentioned: First said (not by name) in 1991, during the flashback while Hagrid described his parents' deaths to Harry; next, the first part of the incantation was said by Lucius Malfoy when he tried to kill Harry, and numerous times in every book following.

Etymology: During an audience interview at the Edinburgh Book Festival on 15 April, 2004 J. K. Rowling said "Does anyone know where avada kedavra came from? It is an ancient spell in Aramaic, and it is the original of abracadabra, which means "let the thing be destroyed". Originally, it was used to cure illness and the "thing" was the illness, but I decided to make the "thing" as in the person standing in front of me. I take a lot of liberties with things like that. I twist them round and make them mine."