a bomb containing a device that makes it explode at a particular time

They dropped a couple of time bombs to destroy the factory.

She is like a ticking timebomb waiting to explode.

a situation that is likely to become difficult to deal with or control

By ignoring the wishes of their employees, the managers are setting/creating a time bomb for themselves. 忽视了雇员的愿望，管理人员等于是在给自己埋下／制造一颗定时炸弹。

The prison governors are sitting on a time bomb (= are having to deal with a bad situation that is likely to become difficult to deal with or control). 监狱长们如同正坐在定时炸弹上。