つと.める 
() task () duties
                                                       
つとめ (n) (1) service, duty, business, responsibility, task, (2) Buddhist religious services
つとめる (v1,vt) (1) to work (for), to be employed (at), to serve (in), (2) to serve (as), to act (as), to fill (the position of), to play the role (of), (3) to conduct a religious service

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Etymologies: 中文字譜 : 説文解字