hesitant
adjective uk/ˈhez.ɪ.tənt/ us/ˈhez.ə.tənt/
犹豫的，踌躇的
If you are hesitant, you do not do something immediately or quickly because you are nervous or not certain.
You seemed a bit hesitant about recommending that restaurant - is something wrong with it? 你似乎不是很愿意推荐那家餐厅——它有什么问题吗？
She gave me a hesitant smile. 她勉强朝我笑了笑。