• 勤務きんむ — duty, service
• 公務こうむ — public service
• 事務じむ — clerical work
• 務つとめる — to serve, to perform duty
• 務つとまる — to be fit for duty

The left part conveys the idea of gathering effort or strength (from 畫/カク), and the right radical 力 (ちから) means “power.” Together, 務 represents focused work or assigned duty.

彼かれは 営業えいぎょうを 務つとめています。
He works in sales.

この 仕事しごとは 私わたしには 務つとまらない。
This job is too much for me.

Usually read as ム in compound words like 事務 or 勤務. When used as a verb, it appears as つとめる (to serve) or つとまる (to be capable of).