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

The tariff ultimatum marks a drastic escalation that strains NATO, the security alliance binding Europe and North America since 1949. —Emma Burrows, Los Angeles Times, 17 Jan. 2026

European Commission President Ursula von der Leyen, who spearheads the bloc’s trade policy, issued a sharp rebuke to the White House’s ultimatum, framing the tariffs not just as a trade dispute but as a test of Western values. —Kevin Breuninger,luke Fountain, CNBC, 17 Jan. 2026

This approach preserves deniability and avoids public ultimatums. —Joel Shulman, Forbes.com, 16 Jan. 2026

However, no ultimatums were made to Harbaugh, nor did any discussions with him reach the stage where final decisions about the makeup of his 2026 staff were communicated. —Jeff Zrebiec, New York Times, 10 Jan. 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