noun
flag waving; flagman; starter (in sports); instigator; leader
Refers to a person who waves a flag to signal or direct, such as a starter in athletics or a traffic guide. Also used figuratively for someone who leads or instigates a movement.
運動会で旗振りの合図でスタートした。
We started at the signal of the flagman at the sports day.
彼は改革運動の旗振
He served as the instigator of the reform movement.