bi·lat·er·al | \ (ˌ)bī-ˈla-t(ə-)rəl \

Definition of bilateral 

1 : affecting reciprocally two nations or parties a bilateral treaty a bilateral trade agreement

2 : having two sides dealing with a bilateral problem

3 biology

a : of, relating to, or affecting the right and left sides of the body or the right and left members of paired organs bilateral nephrectomy

b : having bilateral symmetry

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Other words from bilateral

bilateralism \(ˌ)bī-ˈla-t(ə-)rə-ˌli-zəm \ noun
bilaterally adverb

Did You Know?

Since the prefix bi- means "two" in Latin, bilateral means essentially "two-sided". In the days when there were two superpowers, the U.S. and the Soviet Union regularly engaged in bilateral arms negotiations; such negotiations are much less common today. Sometimes bilateral refers to two sides of the same thing. A bilateral hip replacement, for instance, replaces both hip bones in the same operation. And bilateral symmetry (a term often used by biologists) refers to the fact that, in many organisms (such as humans), the left side is basically the mirror image of the right side.

Examples of bilateral in a Sentence

Recent Examples on the Web

Describing himself as the spokesman for the United States there, Prado, who turns 71 in June, is helping smooth bilateral relations as the U.S. seeks to make the South American country more of an economic and political partner. Guillermo Contreras, San Antonio Express-News, "From Edgewood High School to American diplomacy," 28 May 2018 Niinistö will also hold bilateral meetings with both leaders Monday., "Trump arrives in Scotland for weekend at golf course," 13 July 2018 This year, according to Reuters, South Korea also paid about $857 million for the upkeep of U.S. troops under a 5-year bilateral cost sharing arrangement signed with the U.S. in 2014. Time, "Inside Camp Humphreys, South Korea: America's Largest Overseas Military Base," 13 July 2018 Letting the treaty lapse would send an ominous signal, because every other part of the bilateral arms-control regime left over from the cold war is either dead or crumbling. The Economist, "What Donald Trump and Vladimir Putin ought to talk about in Helsinki," 12 July 2018 This is obviously a game of chess to get China, the EU, Canada to bilateral negotiations to improve our standing on trade imbalances which for decades have gone pretty much ignored. Lynn Brezosky, San Antonio Express-News, "Trade spats ‘new norm’ for sorghum growers, nail biter for Texas manufacturers," 6 July 2018 All parties support the government’s stance in Brexit negotiations: an orderly U.K. exit that protects Ireland’s fundamental interests, including trade and a strong bilateral relationship. Amanda Sloat, Time, "Brexit Could Jeopardize Peace in Northern Ireland—and America Is Ignoring It," 29 June 2018 Another sore point in the bilateral relationship has been China’s ambitious global infrastructure plans, which include projects in New Delhi’s Indian Ocean backyard that domestic analysts worry have a strategic dimension. Karthikeyan Sundaram,, "Trump's Trade War Pushes China Closer to Old Foe India," 28 June 2018 Merkel’s office said both leaders emphasized the importance of continued close bilateral cooperation. Nicole Winfield, The Seattle Times, "New Italian govt vows to create jobs, deport migrants," 2 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'bilateral.' 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 bilateral

1751, in the meaning defined at sense 1

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Statistics for bilateral

Last Updated

14 Sep 2018

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Time Traveler for bilateral

The first known use of bilateral was in 1751

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English Language Learners Definition of bilateral

: involving two groups or countries


bi·lat·er·al | \ (ˈ)bī-ˈlat-ə-rəl, -ˈla-trəl \

Medical Definition of bilateral 

1 : of, relating to, or affecting the right and left sides of the body or the right and left members of paired organs bilateral nephrectomy bilateral tumors of the adrenal glands

2 : having bilateral symmetry

Other words from bilateral

bilateralism \-ˌiz-əm \ noun
bilaterality \(ˈ)bī-ˌlat-ə-ˈral-ət-ē, -ˌla-ˈtral- \ noun plural -ties
bilaterally \(ˈ)bī-ˈlat-ə-rə-lē, -ˈla-trə-lē \ adverb


bi·lat·er·al | \ ˌbī-ˈla-tə-rəl \

Legal Definition of bilateral 

: affecting, obligating, or shared by both parties

Other words from bilateral

bilaterally \-rə-lē \ adverb

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More from Merriam-Webster on bilateral

Spanish Central: Translation of bilateral

Nglish: Translation of bilateral for Spanish Speakers

Britannica English: Translation of bilateral for Arabic Speakers

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