1. 犹豫;迟疑;踌躇
    If you hesitate, you do not speak or act for a short time, usually because you are uncertain, embarrassed, or worried about what you are going to say or do.

    e.g. The telephone rang. Catherine hesitated, debating whether to answer it...
           电话响了。凯瑟琳犹豫了一下要不要去接。
    e.g. She hesitated a long time and then she said 'Yes'.
           她犹豫了很长时间，然后才说“行”。

2. （因有顾虑而）不愿意（做某事）
    If you hesitate to do something, you delay doing it or are unwilling to do it, usually because you are not certain it would be right. If you do not hesitate to do something, you do it immediately.

    e.g. Some parents hesitate to take these steps because they suspect that their child is exaggerating...
           一些家长不愿意采取这些措施，因为他们怀疑自己的孩子在夸大其词。
    e.g. I hesitated to apply the word 'vulnerable' to him but it came into my mind...
           我不愿用“脆弱”这个词来形容他，但它却突然出现在我脑子里了。

3. 尽管给我打电话/ 尽管和我们联系
    You can use hesitate in expressions such as 'don't hesitate to call me' or 'don't hesitate to contact us' when you are telling someone that they should do something as soon as it needs to be done and should not worry about disturbing other people.

hesitate的近义词

    e.g. In the event of difficulties, please do not hesitate to contact our Customer Service Department...
           如果遇到困难，请尽管和我们的客户服务部联系。
    e.g. Please don't hesitate to tell either Mr Schrader or myself should you feel ill again...
           如果你再觉得不舒服，请尽管告诉施拉德尔先生或我本人。