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

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

Macron and Ramaphosa agreed to establish an "annual bilateral dialogue at the level of foreign ministers".

From Barron's • Jul. 11, 2026

In a sign of Zelensky’s elevated status, he got a high-profile bilateral chat with Trump right after the main meeting, where Trump pledged new military support to Ukraine.

From The Wall Street Journal • Jul. 8, 2026

Evidence so far is that months on from Rubio's excited signing of the first MOU, adoption of the bilateral agreements in Africa remains patchy and controversial.

From BBC • Jul. 7, 2026

A White House schedule for Trump’s trip lists bilateral meetings with Rutte and the leaders of Turkey, Syria and Ukraine, in between alliance-wide meals and conferences.

From Los Angeles Times • Jul. 6, 2026

In December, we began a new round of secret bilateral talks with the government.

From "Long Walk to Freedom" by Nelson Mandela

Related Words

• mutual
• reciprocal