ULTIMATUM

[noun] [C] [plural] ultimatums or ultimata - a threat in which a person or group of people are warned that if they do not do a particular thing, something unpleasant will happen to them. It is usually the last and most extreme in a series of actions taken to bring about a particular resultHe gave her an ultimatum - she could either stop seeing her other man and come back to him or it was divorce.On Wednesday night the UN issued its toughest ultimatum to date, demanding that all troops withdraw from the city.