an organized event in which people walk a long distance in order to raise money for charity (= organizations that give money, food, or help free to those who are in need, or that provide money for causes such as medical research)

She is organizing a walkathon from Palms Marine Base in Southern California to Dubois, a distance of over 1,500 miles. 她正在组织一场从南加州的帕尔姆斯海军基地到杜波依斯的徒步马拉松，距离超过1500英里。

Her son was an organizer from an early age; he staged a cancer walkathon at age 12. 她的儿子从小就是一个组织者，在12岁的时候就举办了一次为癌症捐款的徒步马拉松。