noun
knock knees; knock-kneedness
Medical and everyday term for a condition where the knees touch while the ankles are apart. Often contrasted with O脚 (bow legs).
See also: Ｏ脚
Ｘ脚を矯正するために、子供の頃から体操を続けている。
I've been doing exercises since childhood to correct my knock knees.
彼女はＸ脚が気になって、スカートを履くのをためらう。
She is self-conscious about her knock knees and hesitates to wear skirts.