复数：troikas
1.三驾马车[雪橇];并驾拉车的三匹马
2.紧密结合在一起的三个人[三件东西];三巨头,三人执政
1.a group of three people, countries, organizations, etc.
2.a Russian vehicle pulled by three horses walking next to each other
troikastroikastroikas