C1 noun /ˌʌl.tɪˈmeɪ.təm/
Ultimatum
最后通牒
Meaning
a final demand or statement of terms, the rejection of which will result in retaliation
Example
The boss gave him an ultimatum: improve or be fired.
老板给了他一个最后通牒:要么改进,要么被解雇。