Expert
EXPERT', adjective [Latin expertus, from experior, to try. See Experience.]
1. Properly, experienced; taught by use, practice or experience; hence, skillful; well instructed; having familiar knowledge of; as an expert philosopher.
2. Dextrous; adroit; ready; prompt; having a facility of operation or performance from practice; as an expert operator in surgery. It is usually followed by in; as expert in surgery; expert in performance on a musical instrument. Pope uses expert of arms, but improperly.