He was as proficient as any of the other young men in the usual County diversions, hunting, gambling, dancing and politics, and was the best rider of them all; but he differed from all the rest in that these pleasant activities were not the end and aim of life to him.
There are no more uses of "proficiency" in the book.
Show samples from other sources
Not as well as my mother, but I’m pretty proficient."
Kiera Cass -- The Heir
Yvette was by far the most competent of my coworkers, and she and I would often work together on any electrical job requiring proficiency with tools.