ultimatum

noun

ul·​ti·​ma·​tum ˌəl-tə-ˈmā-təm  -ˈmä- 

plural ultimatums or ultimata ˌəl-tə-ˈmā-tə 

-ˈmä-

: a final proposition, condition, or demand

especially : one whose rejection will end negotiations and cause a resort to force or other direct action

Synonyms

• demand
• request
• requirement

Examples of ultimatum in a Sentence

She was given an ultimatum—work harder or lose her job.

issued the ultimatum that the project be finished by the following week, or it would be terminated

Recent Examples on the Web

The announcement came on the deadline day for Trump's ultimatum to the Russian leader, stop the fighting in Ukraine or face additional sanctions. —ABC News, 10 Aug. 2025

Trump’s ultimatums have not prompted the Kremlin to move one inch in its war in Ukraine so far, other than to give the president a meeting. —Freddie Clayton, NBC news, 9 Aug. 2025

Noting Russia’s ongoing attacks on Ukraine, Trump has issued a new ultimatum. —Mark Temnycky, Forbes.com, 7 Aug. 2025

The first time was after an ultimatum by his mother. —Elizabeth Marie Himchak, San Diego Union-Tribune, 5 Aug. 2025

Word History

Etymology

New Latin, from Medieval Latin, neuter of ultimatus final

First Known Use

1731, in the meaning defined above

Rhymes for ultimatum

• latum
• verbatim

Kids Definition

ultimatum

noun

ul·​ti·​ma·​tum ˌəl-tə-ˈmāt-əm  -ˈmät- 

plural ultimatums or ultimata -ə 

: a demand that if rejected will bring about an end of peaceful talks and could lead to forceful action