What is the correct way to spell Alta Madem?

Question

im not sure if i'm even getting the phrase right.
im trying to find the word for when
You have to do ___ or ___ will happen.
know what im talking about?

for example someones "alta madem" would be
You have to propose to me today or I'm leaving you.

what's that called? and how is it spelt?

Answer 1

ultimatum -

: a final proposition, condition, or demand; especially : one whose rejection will end negotiations and cause a resort to force or other direct action


and the correct way to ask is " and how is it spelled?"

Answer 2

ultimatum

Answer 3

ultimatum