keirin
noun [ U or singular ] sports uk/keɪˈrɪn/ us/keɪˈrɪn/
（场地自行车比赛项目）竞轮
a cycling event in which people ride around a track inside a building a number of times. They first all follow a small motor vehicle, and then compete against each other until the end of the race.
She won the women's keirin at the 2012 Olympics. 她在2012奥运的竞轮项目上获胜。