It's possible you're thinking of a different spell or a combination of spells that could be used to create an explosive effect. For example:
* Bombarda: This spell creates a powerful blast of energy, capable of destroying objects and knocking enemies back.
* Diffindo: This spell could be used to break apart an object and then combined with other spells like Bombarda or Stupefy to create a more explosive effect.
It's also possible you're thinking of a fan-made spell or something from another fantasy world.
Can you provide more context? What kind of effect were you imagining? This will help me determine what you're thinking of.