发音：英 [ˈsɜːtnli] 美 [ˈsɜːrtnli]

Certainly是副词，意思是：当然;行;必定;无疑地。

　如：

The public is certainly getting tired of hearing about it.

公众无疑厌倦了听这方面的事。

这里的certainly作副词表示无疑地。

Certainly的同义词有：surely , definitely , ok