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

Ellison's office's lack of substantive response to the ultimatum comes despite the fact that hundreds of Minnesota school board members penned an open letter urging the state to comply with Trump and change its policies to keep males out of girls sports. —Jackson Thompson, FOXNews.com, 11 Oct. 2025

Venus opposite Saturn can feel like an ultimatum in a relationship, a financial obligation that can’t be pushed aside, or simply coming to terms with what is no longer sustainable. —Valerie Mesa, PEOPLE, 11 Oct. 2025

The reasoning behind the ultimatum was not impulsive, per the source. —Lea Veloso, StyleCaster, 9 Oct. 2025

Webber gets an ultimatum — work or his wife. —Maggie Fremont, Vulture, 9 Oct. 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