EXPERT

I. adjective Etymology: Middle English, from Anglo-French & Latin; Anglo-French, from Latin ~us, from past participle of experiri Date: 14th century experienced , having, involving, or displaying special skill or knowledge derived from training or experience, see: proficient ~ly adverb ~ness noun II. noun Etymology: Middle French, from ~, adjective Date: 1535 one with the special skill or knowledge representing mastery of a particular subject, III. intransitive verb Date: circa 1889 to serve as an ~