[ad.ept] n [NL adeptus alchemist who has attained the knowledge of how to change base metals into gold, fr. L, pp. of adipisci to attain, fr. ad- + apisci to reach--more at apt] (1709): a highly skilled or well-trained individual: expert "an ~ at chess"
[2]adept adj (ca. 1691): thoroughly proficient: expert syn see proficient -- adept.ly adv -- adept.ness n