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

• claim
• demand
• dun
• importunity
• requisition

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

At a White House briefing on Tuesday, Press Secretary Karoline Leavitt said agency leaders had the final say on how their employees should view Musk’s ultimatum. —Brian Bennett, TIME, 27 Feb. 2025

Reached for comment about Musk's Monday ultimatum, a White House official told Newsweek federal workers should defer to the heads of their respective departments regarding whether to respond to the email. —Ross Rosenfeld, Newsweek, 26 Feb. 2025

And this past weekend, billionaire Elon Musk — a special adviser to Trump — issued another ultimatum to remaining employees. —Andrea Hsu, NPR, 24 Feb. 2025

Elon Musk issued another controversial ultimatum to federal workers Saturday afternoon, instructing them to report their work accomplishments via email or be fired. —Mary Walrath-Holdridge, USA TODAY, 23 Feb. 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