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

In June, the Department of Education issued a similar ultimatum to California, demanding that the state bar transgender athletes from women’s sports and apologize to female athletes. —Julia Prodis Sulek, Mercury News, 28 Jan. 2026

The City of Johnston has opted to exercise an ultimatum previously given to developers of the Ignit sports complex after the project failed to meet deadlines — sell the property to the city or pay back its grants and costs. —Phillip Sitter, Des Moines Register, 27 Jan. 2026

Georgette believed her mother hoped to reconcile and wanted to use the ultimatum of divorce as a way to push her father to be better. —Daysia Tolentino, Entertainment Weekly, 25 Jan. 2026

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

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