[Gemini Cricket]

From Wikipedia:

Avada Kedavra (Killing Curse)

Pronunciation: /əˈvɑːdə kəˈdɑːvrə/ ə-VAH-də kə-DAH-vrə

Description: Causes a jet of green light(Though Snape hits Dumbledore with red light), and a rushing noise; the curse causes instant death to the victim. It leaves no mark of death. There is no known counter-curse or blocking spell (with the exception of the curse striking another spell midflight, negating both), although the caster can be interrupted, the victim can dodge the curse, hide behind solid objects (which burst into flame when hit by it), or, if the casting wizard is not sufficiently competent, the curse may be completely ineffective as described by Barty Crouch Jr (acting as Alastor Moody) in Goblet of Fire. It is one of the three Unforgivable Curses; the use of this spell on another human being can earn the caster a life sentence in Azkaban.

Survivors: Only two people in the history of the magical world are known to have survived the killing curse - Harry Potter and Voldemort who was only saved by his horcrux. Harry was hit twice directly. Phoenixes can also survive a killing curse. They burst into flame as they would do in old age and are reborn from the ashes. This occurred in Harry Potter and the Order of the Phoenix.

Seen/Mentioned: First said (not by name) at the beginning of the first book when Harry arrives at the Dursley's home. First seen in Goblet of Fire against Muggle Frank Bryce, and in every book following.

Suggested Etymology: During an audience interview at the Edinburgh Book Festival (15 April 2004) 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 it 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."