Silence

Silence was supposed to be a Crowd Control effect in Diablo III, but it was cut prior to game's release.

As in many other fantasy games, Silence would have prevented the enemy from using magic spells and active skills for the duration. The reason why this effect has been canceled is unknown: most likely, it proved to be overpowered in PvP. Against monsters, it is of arguable usefulness due to most enemies not using magic in combat.

Originally, it was planned that Arcane skills would silence enemy on a Critical Hit.

The closest equivalent to this effect in other games is Dim Vision that prevents some (but not all!) monsters from using their special skills.