A

Hannah Abbott ~ Student in Harry's year; sorted to Hufflepuff. [1,7]

Accio ~ A summoning charm which enables a wizard to call a nominated object, even from some distance. [4,6]

Age Line ~ Enchanted barrier, based on the age of the one intending to cross it. [4,16]

Aging Potion ~ Means of disguising youth. [4,16]

Aguamenti ~ Charm to produce water in the quantity required; useful to drink, or extinguish burning buildings. [6,11]

Alchemy ~ Concerned with processes and substances that can turn base metal to gold, and other powerful magic. [1,13]

Alohomora ~ A charm which causes a locked door to open. Used expertly by Hermione Granger. [1,9]

Amortentia ~ The most powerful love potion; creates an infatuation or obsession. [6,9]

Anapneo ~ Incantation for a charm to clear airways; useful with choking. [6,7]

Animagus ~ A wizard who can transform at will into an animal [pl. animagi]. [3,6]

Apparate (Apparation) ~ Magical form of transportation. [2,5]

Aparecium ~ Charm to reveal hidden words: invisible ink for example. [2,13]

Aragog ~ An acromanutula (a species of giant, venomous spider), and leader of a spider group in the Forbidden Forest. [2,15]

Arithmancy ~ An ancient system of divination by numbers. [3,4]

Armando Dippet: Master or Moron? ~ Biography, by Rita Skeeter. [7,13]

Auror ~ Wizard specializing in detecting and detaining Dark Wizards. [4,11]

Avada Kedavra ~ The Killing Curse. No counter curse, no way of blocking it; only one person has been known to survive it. An Unforgivable Curse. [4,14]

Avis ~ Charm to produce birds; useful wand test. [4,18]

Avery ~ A Death eater. [4,27]

Azkaban ~ The wizard prison. [2,12]