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

Trump is scheduled for a welcome ceremony and bilateral talks on Thursday, followed by a visit with Xi to the Temple of Heaven and then a state dinner, according to the White House’s itinerary.

From Barron's • May 12, 2026

Trump will join Chinese President Xi Jinping on Friday for a bilateral tea and working lunch before flying home.

From Barron's • May 11, 2026

On the economic front, they expect the agenda to reinforce short-term stabilization in bilateral relations.

From The Wall Street Journal • May 8, 2026

The Vatican described the talks as “cordial” and said “the shared commitment to cultivate good bilateral relations between the Holy See and the United States of America was renewed.”

From The Wall Street Journal • May 7, 2026

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

From "Long Walk to Freedom" by Nelson Mandela

Related Words

• mutual
• reciprocal