己おのれの分ぶんを尽つくす

expression, godan verb (-su)

do one's part; fulfill one's duty

Rare, formal expression meaning to carry out one's assigned role or responsibility. The phrase uses 己 (oneself) and 分 (one's lot/station), implying a sense of duty tied to one's position.

• 彼かれは常つねに己おのれの分ぶんを尽つくすことを心こころがけている。

  He always strives to do his part.