ultimatum
Concise Oxford English Dictionary © 2008 Oxford University Press:
ultimatum/ʌltɪˈmeɪtəm/
▶noun (pl. ultimatums or ultimata /-tə/) a final demand or statement of terms, the rejection of which will result in retaliation or a breakdown in relations.
– origin C18: from L., neut. past part. of ultimare ‘come to an end’.
'ultimatum' also found in these Oxford entries:
