timid

The timid kitten hid behind the sofa when the doorbell rang.

(Chinese) 门铃响时，那只胆小的猫崽躲到了沙发后面。

He was too timid to ask his boss for a raise, despite his hard work.

(Chinese) 尽管工作努力，他还是太胆怯了，不敢向老板提加薪。