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

This post comes after Vice President Vance on Wednesday also issued an ultimatum of sorts about the war, now in its fourth year. —The Hill Staff, The Hill, 23 Apr. 2025

The Trump administration’s ultimatums seem mostly aimed at Ukraine, even though Russian strongman Vladimir Putin has made no major concessions so far and snubbed Trump’s demands for a ceasefire to allow peace talks to gain traction. —Dave Goldiner, New York Daily News, 23 Apr. 2025

Following Harvard’s refusal to capitulate to the letter’s ultimatum, Donald Trump threatened to revoke the university’s tax-exempt status. —Stuart Anderson, Forbes.com, 20 Apr. 2025

The letter noted that the Administration’s demands contravene the First Amendment and federal law and rejected the premise of the ultimatum. —Jeannie Suk Gersen, New Yorker, 15 Apr. 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