Proficient /(?)/

Pro·fi·cient

Proficient

n.
  1. One who has made considerable advances in any business, art, science, or branch of learning; an expert; an adept; as, proficient in a trade; a proficient in mathematics, music, etc.

Proficient

a.
  1. Well advanced in any branch of knowledge or skill; possessed of considerable acquirements; well-skilled; versed; adept,