bilateral

adjective

bi·​lat·​er·​al (ˌ)bī-ˈla-t(ə-)rəl 

1

: affecting reciprocally two nations or parties

a bilateral treaty

a bilateral trade agreement

2

: having two sides

dealing with a bilateral problem

3

biology

a

: of, relating to, or affecting the right and left sides of the body or the right and left members of paired organs

bilateral nephrectomy

b

: having bilateral symmetry

bilateralism

(ˌ)bī-ˈla-t(ə-)rə-ˌli-zəm 

noun

bilaterally adverb

Did you know?

Since the prefix bi- means "two" in Latin, bilateral means essentially "two-sided". In the days when there were two superpowers, the U.S. and the Soviet Union regularly engaged in bilateral arms negotiations; such negotiations are much less common today. Sometimes bilateral refers to two sides of the same thing. A bilateral hip replacement, for instance, replaces both hip bones in the same operation. And bilateral symmetry (a term often used by biologists) refers to the fact that, in many organisms (such as humans), the left side is basically the mirror image of the right side.

Examples of bilateral in a Sentence

Recent Examples on the Web

In the years since that hopeful summit, bilateral trade has continued to increase, but it has been overshadowed by escalating tensions. —Tomohiko Taniguchi, Foreign Affairs, 16 Apr. 2024

Central to the arrangement is an agreement by Saudi Arabia to normalize relations with Israel, which the United States would then reward with a new bilateral U.S.-Saudi security partnership. —Karen Deyoung, Washington Post, 12 Apr. 2024

Of course, boosting investments in Vietnam is something championed by Washington, which in September elevated bilateral ties to a Comprehensive Strategic Partnership when President Joe Biden visited Hanoi. —Charlie Campbell, TIME, 12 Apr. 2024

Image Moving Toward the Mainstream On Nov. 8, a coalition of Black clergy members ran an advertisement in The New York Times calling for a bilateral cease-fire. —Sheera Frenkel, New York Times, 12 Apr. 2024

Among other topics that Yellen plans to discuss with her Chinese counterparts include bilateral cooperation on countering illicit finance and working on global issues such as climate change and financial stability, according to the Treasury Department. —Laura He, CNN, 5 Apr. 2024

Many allies, appearing surprised by the figure, have been asking whether existing bilateral aid being doled out would count toward the $100 billion commitment, or if this would be an entirely different commitment. —John Hudson, Washington Post, 4 Apr. 2024

Under the terms of the bilateral memorandum of understanding, the countries will jointly develop tests and perform at least one testing exercise on a publicly accessible model. —David Meyer, Fortune, 2 Apr. 2024

In light of this, analysts in Pakistan have questioned the wisdom of Mr. Dar’s comments on restoring bilateral trade. —Hasan Ali, The Christian Science Monitor, 1 Apr. 2024

Word History

First Known Use

1751, in the meaning defined at sense 1

Phrases Containing bilateral

• bilateral symmetry

Kids Definition

bilateral

adjective

bi·​lat·​er·​al (ˈ)bī-ˈlat-ə-rəl 

-ˈla-trəl

1

: having or involving two sides or parties

a bilateral treaty

2

: characterized by bilateral symmetry

bilaterally

-ē

adverb

Medical Definition

bilateral

adjective

bi·​lat·​er·​al (ˈ)bī-ˈlat-ə-rəl, -ˈla-trəl 

1

: of, relating to, or affecting the right and left sides of the body or the right and left members of paired organs

bilateral nephrectomy

bilateral tumors of the adrenal glands

2

: having bilateral symmetry

bilateralism

-ˌiz-əm 

noun

bilaterality

(ˈ)bī-ˌlat-ə-ˈral-ət-ē, -ˌla-ˈtral- 

noun

plural bilateralities

bilaterally

(ˈ)bī-ˈlat-ə-rə-lē, -ˈla-trə-lē 

adverb

Legal Definition

bilateral

adjective

bi·​lat·​er·​al ˌbī-ˈla-tə-rəl 

: affecting, obligating, or shared by both parties

bilaterally

-rə-lē

adverb