|"We must've been through hundreds of books already and we can't find him anywhere —"|
Avery is the surname of a pure-blood wizarding family, and one of the Sacred Twenty-Eight. Its members have traditionally attended Hogwarts School of Witchcraft and Wizardry and recent members have been Death Eaters.
Two members of different ages are mentioned, but their first names are unknown.
Avery is a surname of ambiguous origin. Some scholars believe that the name is derived from Every, which is the name of a county in Normandy, or Évreux, a noble family that ruled Navarra from 1328 to 1441.