1. 当权派;头儿：3)not have a dog's chance毫无机会 | 4)top dog当权派;头儿 | 5)treat /use sb. like a dog不把某人当人看

2. 优胜者：(3)Big dog要人 | (4)Top dog 优胜者 | (5)Clver dog聪明的小孩

3. 支配地位：top 顶部 | top-dog 支配地位 | top-down 自顶向下

4. 有优势的人,国家,团体等：20. separate the sheep form the goats.把好人同坏人分开. | 21. top dog.有优势的人,国家,团体等. | 22. like a cat on hot bricks.如坐针毡;像热锅上的蚂蚁.

noun

1. a person who is in charge

e.g. the head of the whole operation

Synonym: headchief