bilatérale

Bilatérale is the feminine form of the French adjective bilatéral and describes something that relates to two sides or involves two parties. The term is used across disciplines to indicate a two-sided relationship, structure, or condition.

In biology, bilateral refers to bilateral symmetry, a body plan with left and right halves that are near-mirror images. Many animals, including humans, exhibit this symmetry. The term also describes paired structures or organs, such as eyes and limbs.

In medicine, bilateral denotes processes or conditions affecting both sides of the body. Examples include bilateral symptoms, bilateral nerve blocks, and bilateral organ involvement in disease.

In international relations and law, a bilateral agreement or treaty is negotiated between two states or parties, as opposed to multilateral agreements that involve three or more. Bilateral arrangements are common in trade, defense, and cultural exchanges.

In economics and finance, bilateral terms describe transactions or agreements between two counterparties rather than within a broader group.

Etymology: bilatérale derives from Latin bi- meaning two and latus meaning side, transmitted through French.

See also: unilateral, multilateral, bilateralism. The concept contrasts with unilateral (one-sided) and multilateral (involving multiple parties), highlighting how a given issue or arrangement engages two sides rather than many.