waver
verb [ I ] uk/ˈweɪ.vər/ us/ˈweɪ.vɚ/
（尤指暂时地）动摇
to lose strength, determination, or purpose, especially temporarily
I'm afraid my concentration began to waver as lunch approached. 恐怕我的注意力在临近午饭时要开始下降了。
He has never wavered in his support for the leader. 他对领袖的支持从未动摇过。
（在两个选择之间）踌躇，犹豫不决
If you waver between two possibilities, you cannot decide which of them to choose or you keep choosing one way and then the other.
"What are you going to have?" "Er, I'm wavering between the soup and the mushroom quiche." “你要吃什么？”“哦，我正在犹豫是喝汤还是吃乳蛋饼。”