ˈbækˌbəʊn ˈbækˌboʊn ˈkiː.stəʊn ˈlɪnt͡ʃˌpɪn ˈmeɪn.steɪ pin inserted through an axletree to hold a wheel on a central cohesive source of support and stability faith is his anchor the keystone of campaign reform was the ban on soft money he is the linchpin of this firm