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 of ultimatum

• 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

But again, the three-day ultimatum, the risk to designate us a supply chain. —CBS News, 28 Feb. 2026

The ultimatum constitutes perhaps the biggest crisis in the company’s five-year existence, writes Jeremy Kahn. —Diane Brady, Fortune, 26 Feb. 2026

As the Meridian Empire sets out to usurp wealthy colonies and crush the pirate republic, Cat is faced with an ultimatum – turn in the fearsome Valerian Kane, the only man she’s ever loved and the biggest threat to the Empire, or die. —Clare Mulroy, USA Today, 26 Feb. 2026

Trust is built over time, but the blustery ultimatum that Hegseth has set leaves Anthropic with no good options. —Idrees Kahloon, The Atlantic, 26 Feb. 2026

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