/ɪˈfem.ɚ.əl/
lasting or used for only a short period of time SYN short-lived
If you describe something as ephemeral, you mean that it lasts only for a very short time. [Formal]
He talked about the country’s ephemeral unity being shattered by the defeat…
他谈到战败使得该国短暂的统一彻底破灭。
These paintings are in some ways a reminder that earthly pleasures are ephemeral.
这些画在某种意义上提醒人们世俗的享乐是短暂的。