proficient

adj

1. Good at something; skilled; fluent; practiced, especially in relation to a task or skill.

   “He was a proficient writer with an interest in human nature.”

   “By constant playing and experimenting with these he learned to tie rude knots, and make sliding nooses; and with these he and the younger apes amused themselves. What Tarzan did they tried to do also, but he alone originated and became proficient.”

noun

1. An expert.

   “The colonel now addressed me, […] adding, "I hope we shall send you to your regiment up the country quite a proficient, and calculated to reflect credit on your instructors in the Zubberdust Bullumteers."”

   “Why not subpoena as well the clerical proficients?”