She left me, and I continued some time walking up and down the passages of the house and inspecting every corner that might afford a retreat to my adversary.
But revenge kept me alive; I dared not die and leave my adversary in being.
I resolved, therefore, that if my immediate union with my cousin would conduce either to hers or my father’s happiness, my adversary’s designs against my life should not retard it a single hour.
Think not, Walton, that in the last moments of my existence I feel that burning hatred and ardent desire of revenge I once expressed; but I feel myself justified in desiring the death of my adversary.
I did not weep, but I knelt down and with a full heart thanked my guiding spirit for conducting me in safety to the place where I hoped, notwithstanding my adversary’s gibe, to meet and grapple with him.
If for one instant I had thought what might be the hellish intention of my fiendish adversary, I would rather have banished myself forever from my native country and wandered a friendless outcast over the earth than have consented to this miserable marriage.
I was anxious and watchful, while my right hand grasped a pistol which was hidden in my bosom; every sound terrified me, but I resolved that I would sell my life dearly and not shrink from the conflict until my own life or that of my adversary was extinguished.
There are no more uses of "adversary" in the book.
Show samples from other sources
Then, again, our military training is in many respects superior to that of our adversaries.
Thucydides -- Pericles’s Funeral Oration
Finally, it was rumored, there would be complete information-sharing among all of these previously disconnected and even adversarial entities, and when they were coordinated, and once all the health data they’d collected was shared, most of this made possible through the Circle and more important, TruYou, viruses could be stopped at their sources, diseases would be tracked to their roots.