Definition of bilateral
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 nephrectomyb : having bilateral symmetry
bilateralismplay \-t(ə-)rə-ˌli-zəm\ noun
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.
First Known Use of bilateral
BILATERAL Defined for English Language Learners
Definition of bilateral for English Language Learners
: involving two groups or countries
Medical Definition of bilateral
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
bilaterality\(ˈ)bī-ˌlat-ə-ˈral-ət-ē, -ˌla-ˈtral-\play noun plural
bilaterally\(ˈ)bī-ˈlat-ə-rə-lē, -ˈla-trə-lē\play adverb
Legal Definition of bilateral
: affecting, obligating, or shared by both parties
Seen and Heard
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