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Webster 1913 Edition

adv.

In a ranting manner.

rantingly ‎(comparative more rantingly, superlative most rantingly)

With ranting; speaking loudly and angrily.
- 1738, Thomas Morgan, The Moral Philosopher
  In short, these are only two different Species of Distraction: The Enthusiast is deeply and sullenly out of his Wits, and the Atheist is merrily and rantingly mad, and both are owing to the same general Cause […]