English Reference
adjective · noun

bilateral

adj. · n.
US /baɪˈɫætɝəɫ/ UK /baɪlˈætəɹəl/ bi·lat·er·al

  1. 01 C1 Advanced Formal

    adj.involving two groups or countries, especially in an official agreement.

    adj.involving two parties, groups, or nations, typically in a formal or diplomatic context.

    Simple

    The two countries signed a bilateral trade agreement to lower taxes on imports.

    In context

    The bilateral negotiations stalled when neither delegation was willing to compromise on the sensitive issue of maritime borders.

    Usage

    Commonly used in political and legal contexts to describe treaties or talks.

    mutualtwo sidedjoint
  2. 02 C1 Advanced Technical Science

    adj.having two sides or parts that are the same.

    adj.relating to or having two sides; specifically having symmetry where the left and right sides are mirror images.

    Simple

    Most animals, including humans, have bilateral symmetry.

    In context

    The biologist noted that the specimen exhibited perfect bilateral symmetry, with identical markings on both the left and right wings.

  3. 03 C2 Proficiency AcademicTechnical

    adj.tracing your family history through both your mother's and father's side.

    adj.relating to a system of kinship where descent is traced through both the maternal and paternal lines.

    Simple

    In many modern societies, people follow a bilateral system of family history.

    In context

    The researcher argued that bilateral descent patterns provided a more flexible social structure than strictly patrilineal systems.

    unilineal
  4. 04 C1 Advanced Formal

    n.a formal meeting between two people or groups.

    n.a formal discussion or meeting held between two parties, especially in diplomacy.

    Simple

    The president held a bilateral with the prime minister before the main summit.

    In context

    Following the general assembly, the two leaders retired to a private room for a bilateral to discuss regional security.

Usage bilateral relations

However, Russia’s 2022 invasion of Ukraine prompted Japan to impose sanctions on personnel and entities linked to Moscow, souring bilateral relations.

The Guardian· 13 Aug 2026

Justice minister Liisa Pakosta told the BBC that Estonia would not rent jail cells to other countries while it was housing criminals from Sweden in its half-empty Tartu prison under a bilateral deal.

The Guardian· 13 Aug 2026

From bi- + lateral.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Level C1 · Advanced
Frequency Frequent
Updated