bilateral

American  

[bahy-lat-er-uhl] / baɪˈlæt ər əl /

adjective

1. pertaining to, involving, or affecting two or both sides, factions, parties, or the like.

   a bilateral agreement; bilateral sponsorship.

2. located on opposite sides of an axis; two-sided, especially when of equal size, value, etc.

3. Biology. pertaining to the right and left sides of a structure, plane, etc.

4. Chiefly Law. (of a contract) binding the parties to reciprocal obligations.

5. through both parents equally.

   bilateral affiliation.

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noun

1. Informal. a bilateral agreement, especially regarding international trade.

bilateral British  

/ baɪˈlætərəl /

adjective

1. having or involving two sides

2. affecting or undertaken by two parties; mutual

   a bilateral treaty

3. denoting or relating to bilateral symmetry

4. having identical sides or parts on each side of an axis; symmetrical

5. sociol relating to descent through both maternal and paternal lineage Compare unilateral

6. relating to an education that combines academic and technical courses

7. a bilateral meeting

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Other Word Forms

• bilateralism
  noun
• bilateralness
  noun
• bilaterally
  adverb

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Etymology

Origin of bilateral

First recorded in 1765–75; bi- ¹ + lateral

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Explanation

When something is bilateral it has two sides or it affects both sides of something. Discussions between two political parties are called bilateral because both sides get to share their views. Bilateral comes from Latin: bi means "two" and lateralis means "belonging to the side." Debates about issues can be described as bilateral — as long as people on both sides get to speak. However, bilateral can describe anything with two sides, like some of the organs in the body: the brain, heart and lungs all have two distinct sides.

Example Sentences

See Examples For:

bilateral

On Monday, the Eagles announced he had been diagnosed with a deep-vein thrombosis and bilateral pulmonary emboli.

From MarketWatch ● Oct. 19, 2026

Hurts has been diagnosed with deep vein thrombosis and a bilateral pulmonary emboli, the statement said, meaning a blood clot has traveled from his legs to his lungs.

From Los Angeles Times ● Oct. 19, 2026

Last year, bilateral trade reached $2.7bn, marking a recovery to pre-pandemic levels, mostly fuelled by Chinese exports to North Korea.

From BBC ● Oct. 15, 2026

The institute took part in a bilateral training exercise with China earlier this year against the potential outbreak of an infectious disease.

From The Wall Street Journal ● Oct. 5, 2026

The government and the ANC agreed to continue bilateral talks to work toward a solution.

From "Long Walk to Freedom" by Nelson Mandela

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Related Words

• mutual
• reciprocal

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