uni·​lat·​er·​al | \ˌyü-ni-ˈla-tə-rəl, -ˈla-trəl\

Definition of unilateral 

1a : done or undertaken by one person or party

b : of, relating to, or affecting one side of a subject : one-sided

c : constituting or relating to a contract or engagement by which an express obligation to do or forbear is imposed on only one party

2a : having parts arranged on one side a unilateral raceme

b : occurring on, performed on, or affecting one side of the body or one of its parts unilateral exophthalmos

3 : unilineal

4 : having only one side

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Other Words from unilateral

unilaterally adverb

Did You Know?

The world is a smaller place than it used to be, and we get uncomfortable when a single nation adopts a policy of unilateralism—that is, acting independently with little regard for what the rest of the world thinks. A unilateral invasion of another country, for instance, usually looks like a grab for power and resources. But occasionally the world welcomes a unilateral action, as when the U.S. announced unilateral nuclear-arms reductions in the early 1990s. Previously, such reductions had only happened as part of bilateral ("two-sided") agreements with the old Soviet Union. Multilateral agreements, on issues such as climate change, often involve most of the world's nations.

Examples of unilateral in a Sentence

Our country is prepared to take unilateral action.

Recent Examples on the Web

The North’s demands are likely to include the loosening of United Nations and unilateral sanctions, as well as a formal declaration to end the Korean War. The Editorial Board, WSJ, "Moon Shot in Korea," 19 Sep. 2018 To answer Paul's question: he's supposed to accept the American intelligence community's unilateral finding that Russia interfered in the 2016 election. Michelle Ruiz, Vogue, "Donald Trump Doesn't Care About Democracy. He Only Cares About Himself.," 17 July 2018 China’s Global Times newspaper, which is published by the Communist Party, called on Japan, South Korea and the U.S. to immediately lift all unilateral sanctions on North Korea. Fortune, "As North Korea Vows to Halt Nuclear Testing, Trump Hails 'Big Progress'," 21 Apr. 2018 On Thursday, McInnis would not comment on the authority's discussion of unilateral action. Mark Schleifstein, NOLA.com, "East bank levee authority could return drainage, pump operations to St. Bernard Parish," 17 May 2018 The vote was finally held amid a violent crackdown by police sent in by Madrid, and the unilateral declaration of a new Catalan republic that followed was never implemented after central authorities seized control over the region. Aritz Parra, The Seattle Times, "Spanish, Catalan leaders meet to bridge gap over secession," 9 July 2018 What was once a one-shot meeting became the beginning of a process; the objective of unilateral disarmament was transformed into a mission of building relationships. Mira Rapp-hooper, Washington Post, "The Singapore summit’s three big takeaways," 12 June 2018 Bolton has repeatedly suggested the Libya model of unilateral disarmament for North Korea, most recently on Sunday. NBC News, "Trump seeks to placate Kim Kong Un over uncertain summit," 18 May 2018 Talking about the Winter Olympics is positive but is a long way from unilateral nuclear disarmament. Charlie Campbell / Beijing, Time, "However Small, North Korea's Olympics Talks Are a Victory," 8 Jan. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'unilateral.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of unilateral

1802, in the meaning defined at sense 1a

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13 Nov 2018

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The first known use of unilateral was in 1802

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English Language Learners Definition of unilateral

: involving only one group or country


uni·​lat·​er·​al | \ˌyü-ni-ˈlat-ə-rəl, -ˈla-trəl \

Medical Definition of unilateral 

: occurring on, performed on, or affecting one side of the body or one of its parts unilateral exophthalmos

Other Words from unilateral

unilaterally \ -​ē \ adverb


uni·​lat·​er·​al | \ˌyü-nə-ˈla-tə-rəl \

Legal Definition of unilateral 

1 : done or undertaken by one party a unilateral mistake as to the terms

2 : of, relating to, or affecting one side of a subject

3 : containing a promise to perform made by only one party especially because the other has already performed (as by paying an amount) an option contract is unilateral

Other Words from unilateral

unilaterally adverb

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More from Merriam-Webster on unilateral

Spanish Central: Translation of unilateral

Nglish: Translation of unilateral for Spanish Speakers

Britannica English: Translation of unilateral for Arabic Speakers

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by force of circumstances

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