E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A loud ranting voice. In the old mysteries all tyrants were made to speak in a rough ranting manner. Thus Bottom the Weaver, after a rant to show his quality, exclaims, Thats Ercles vein, a tyrants vein; and Hamlet describes a ranting actor as out-heroding Herod.