irresistibleness

irresistible +‎ -ness

irresistibleness (uncountable)

1. The quality of being irresistible.
   • 1854, Theodor Mommsen, The History of Rome, Book V‎:

     Once Rome, fully conscious of the irresistibleness of her power by land, had transferred her superiority also to the other element; now the mighty state was powerless at sea and, as it seemed, on the point of also losing its dominion at least over the Asiatic continent.

   • 1897, Lilian Bell, From a Girl's Point of View‎:

     If he could get our point of view and let some woman take a hand at him, she might efface his irresistibleness and make a man of him.