ad.

1. 确实，无疑，一定
   She surely seems happy.

   她看来肯定很快活。

2. 稳当地
   He walked slowly but surely.

   他走得很慢，但却很稳当。

3. 想必
   Surely you don't believe that!

   你想必不会相信那种事吧！

4. 【美】【口】当然
   --"Are you going with us?" --"Surely."

   —“你和我们一起去吗？” —“当然啦！”

adv.

1. it must be true that (used for emphasis).
   ▸certainly.
   ▸ [as exclam.] N. Amer. informal of course.
2. with assurance.