Expert Defined
n.
1. A person with a high degree of skill in or knowledge of a certain subject.
2.
1. The highest grade that can be achieved in marksmanship.
2. A person who has achieved this grade.
adj. (ĕk'spûrt, ĭk-spûrt')
Having, involving, or demonstrating great skill, dexterity, or knowledge as the result of experience or training.