Greif cannon
= Greif cannon
{wiki=Greif_cannon}
The term "Greif cannon" does not appear to have a widely recognized meaning in historical or contemporary contexts. It’s possible that you might be referring to a specific type of artillery or perhaps making a typo or confusion with another term, such as "Grief cannon" in a gaming context or "Griefing," which refers to the act of harassing or annoying other players in online games.