proficiency
>1540s, probably from abstract noun suffix -cy + Latin proficientem (nominative proficiens), present participle of proficere "accomplish, make progress; be useful, do good; have success, profit," from pro "forward" (see pro-) + combining form of facere "to make, do" (from PIE root *dhe- "to set, put").
source: [輪るピングドラムのペンギン１号がきゅうりを高速で輪切りにするGIF画像｜無料GIF画像検索 GIFMAGAZINE 78790]
noun
«…の» 熟達, 技量 «in, at, of» .
e.g. he demonstrated his proficiency in Chinese.: 彼は中国語の技量を実演した。