proficientyoudaoicibaDictYouDict[proficient 词源字典]
proficient: see profit
[proficient etymology, proficient origin, 英语词源]
proficient (adj.)youdaoicibaDictYouDict
1580s, back-formation from proficiency or else from Old French proficient (15c.), from Latin proficientem (nominative proficiens), present participle of proficere "to make progress, go forward, effect, accomplish, be useful" (see proficiency). Related: Proficiently.