As per google- "To destroy completely."
The barons stand beside Arthur, and would make him king, because it is "God's will", and because he is king, they deem their loyalty with him, and would protect him at all cost.
So the barons are loyal, and would give their all to defend the rightful king
hope this helps
Mrs. Putnam gets it into her head that there must be a gigantic conspiracy between the Prince of Darkness and some of the supposedly God-fearing folk of Salem. That's what she means when she says "There are wheels within wheels in this village, and fires within fires!"
