E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Othman, Osman, or Othoman,
surnamed the Conqueror. Founder of the Turkish power, from whom the empire is called the Ottoman, and the Turks are called Osmans, Othmans, Osmanli, etc. Peter the Great, being hemmed in by the Turks on the banks of the Pruth, was rescued by his wife, Catherine, who negotiated a peace with the Grand Vizier.