top dog

 Longman Dictionary of Contemporary English 5++朗文当代英语 5++LDOCE 5++朗文 5++ˌtop ˈdog noun [countable]  the person who has the most power in a group, especially after a struggle 〔尤指经过争斗后〕最有权的人 He always wanted to be the one in control, the top dog. 他总是想执掌大权，成为第一把手。

ˌtop ˈdog nounChineseSyllable  

top dog
ˌtop ˈdog noun [countable]
the person who has the most power in a group, especially after a struggle:
    He always wanted to be the one in control, the top dog.

top dogBrE /ˌtɒp ˈdɒɡ/ 🔊NAmE /ˌtɑːp ˈdɔːɡ/ 🔊 noun [usually singular] (informal) a person, group or country that is better than all the others, especially in a situation that involves competition （尤指竞争中的）夺魁者，优胜者