Tiscali - Harry Potter and the Chamber of Secrets

Accio: Summoning spell.

Acid Pops: Wizarding sweets that burn holes in your tongue. Available at Honeydukes in Hogsmeade.

Aconite: Plant used in potions. Also known as Monkshood or Wolfsbane.

Agrippa: Name of a wizard depicted on a wizard trading card.

Alchemy: Medieval science that was founded on the search to turn any metal into gold.

Alohomora: Door-unlocking spell.

Animagi: Wizards who can turn themselves into animals at will. The singular form is animagus.

Aparecium: Spell to make invisible ink visible.

Apparate: To transport oneself instantly to any destination. Apparating is difficult and must not be done without a licence from the Department of Magical Transportation. There is a danger of splinching.

Aragog: Name of a huge spider that lives in the Forbidden Forest.

Arithmancy: Ancient study of the magical properties of numbers.

Astronomy: Study of the stars and planets.

Aunt Marge: Dudley Dursley's dreadful aunt, sister to Vernon Dursley and no friend of Harry's.

Auror: Professional Dark-wizard-catcher.

Avada Kedavra: Killing curse. It brings about instant death in a flash of green light. There is no way of blocking it. It is one of the three Unforgivable Curses.

Azkaban: Prison fortress where wizarding criminals are sent. Guarded day and night by the terrifying Dementors, who drain peace, hope and happiness out of any human who comes too close to them.