Meaning of 務める in Japanese

Definition of 務める

つとめる(tsutomeru) 【勤める ·務める】

(v1, vt) to work (for); to be employed (at); to serve (in)
私の父は外務省に勤めている。
My father serves in the Foreign Ministry.
to serve (as); to act (as); to fill (the position of); to play the role (of)
to conduct a religious service

ぎちょうをつとめる(gichouwotsutomeru) 【議長を務める】

彼かれはジョンにかわりを務めるように命じた。

He appointed John to act as his deputy.