As Meddling Mage enters the battlefield, choose a nonland card name.
Spells with the chosen name can't be cast.
No one can cast spells or activate abilities between the time a card is named and the time that Meddling Mage's ability begins to apply.
Spells with the chosen name that somehow happen to already be on the stack when Meddling Mage enters the battlefield aren't affected by Meddling Mage's ability.