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

Derived Forms

• bilateralness
  noun
• bilateralism
  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

Both sides have stepped up their long-range drone and missiles attacks since a series of bilateral talks mediated by the United States earlier this year appeared to stall.

From Barron's • May 27, 2026

Under the makeover, encounters between Americans and Venezuelans in Caracas feel less like bilateral meetings than audiences.

From The Wall Street Journal • May 24, 2026

Earlier this year, Somalia — whose seaports, airports and military bases have been used for Emirati materiel transfers, investigators say — severed bilateral agreements with the UAE.

From Los Angeles Times • May 24, 2026

The two sides are currently negotiating the final text of a broader bilateral deal, but further details of the negotiations remain sketchy.

From BBC • May 23, 2026

To those who are genuinely concerned, I push a button to say, “I have spastic bilateral quadriplegia, also known as cerebral palsy. It limits my body, but not my mind.”

From "Out of My Mind" by Sharon M. Draper

Related Words

• mutual
• reciprocal