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
• bilaterally adverb
• bilateralness noun

Etymology

Origin of bilateral

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

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

That’s a generous reading of the bilateral zeitgeist at a tempestuous moment.

From Los Angeles Times • Apr. 14, 2026

He has engaged in countless bilateral forums, work groups and discussions about immigration, drug trafficking, cross-border commerce and other concerns, and generally received good marks from U.S. officials.

From Los Angeles Times • Apr. 14, 2026

Chinese foreign ministry spokeswoman Mao Ning on Wednesday called Spain "an important partner of China within the EU", adding that Sanchez's visit offers a chance to "promote bilateral relations to an even higher level".

From Barron's • Apr. 12, 2026

Personal relations have long helped boost bilateral ties shaped by shifting strategic interests that have at times been strained.

From Barron's • Apr. 8, 2026

All of our previous bilateral discussions had been laying the groundwork for these talks, which took place at the World Trade Centre, a modem exhibition center near Jan Smuts Airport in Johannesburg.

From "Long Walk to Freedom" by Nelson Mandela

Related Words

• mutual
• reciprocal