Surprise means 驚 in a single chinese word, but it is more appropriate with two words grouping together like 驚喜, 驚異, 吃驚, 驚訝, 驚奇 etc., It can be a noun, adjective, or adverb, it depends on how you group them together and where you place them.
As a surprise for her -至於她一個驚喜
Oh you surprised me! - 噢,你讓我吃驚!
I want to surprise them - 我希望讓他們感到意外
I was surprised to hear/see - 我驚奇地聽到/看到
It's not surprising - 這並不令人驚訝
It took them all by surprise - 使他們所有的驚喜
When you look up " surprise" it will display all the possible combinations, you need to choose one that is more appropriate for your application.