Hedge wizard

A hedge wizard (or hedge mage) is usually a negative term to call wizards and mages who are not liked by the Kirin Tor. Magistrate Marduke says that a "hedge mage" is a rogue wizard that never received their formal training from Dalaran.

As a child, Khadgar learned from most of his lessons that non-Dalaran mages, wild, untrained, and self-taught wizards without restraint, control, and thought, always ended in the same fashion with a bad end, and sometimes, though not often, destroying a large amount of the surrounding countryside with them.

Hedge mages often use the smoke of an herb known as Witchbane to draw evil from its hiding places.

Certain renegade wizards have also been known to create their own golems to protect their secret dens and lairs.

First War
During the First War, Northshire Abbey was attacked by a band of brigands that had been convinced by enemy agents to fight against the crown. Among them were some rogue conjurers.

Third War
Though most contemporary human and high elven mages bow to the sovereignty of Dalaran and the Kirin Tor, there are a great many who choose to delve into the secrets of magic by themselves. Considered to be non-sanctioned renegades by the Kirin Tor, these rogue mages strive to expand their knowledge of magic and spellcraft beyond the constraints of what most other wizards believe to be safe or morally acceptable.

World of Warcraft
The Defias Brotherhood has hedge mages in its ranks, including the Defias Rogue Wizards and Defias Renegade Mages.

Many other human factions like the Syndicate and the Cult of the Damned also have evil wizards and mages among their ranks, like Ras Frostwhisper who was in his life a hedge mage of Stromgarde.

In the RPG
Most people do not make a distinction between sorcerers and wizards, although "hedge wizard" is used as a pejorative term by wizards against sorcerers.

Beve Perenolde and Pai Stormbringer were both described as being both rogues and wizards, studying away for the teachings of the Kirin Tor.