English Reference
noun · verb

treaty

n. · v.
US /ˈtɹiti/ UK /tɹˈiːti/ treaty UK spelling treaties, treaty's

  1. 01 B2 Upper Intermediate Formal Law

    n.a formal agreement between countries, usually about peace, trade, or working together.

    n.a formal, legally binding agreement concluded by subjects of international law, such as states or international organizations.

    Simple

    The two countries signed a peace treaty to end the long war.

    In context

    The environmental treaty requires all signatory nations to reduce their carbon emissions by twenty percent over the next decade.

    Usage

    Often used with verbs like 'sign', 'ratify', or 'violate'.

  2. 02 C2 Proficiency Archaic

    n.the act of discussing or negotiating to reach an agreement.

    n.the process of negotiation or discussion aimed at reaching a settlement or compact.

    Simple

    The two kings were in treaty for many months before the borders were fixed.

    In context

    The ambassadors remained in treaty for several weeks, though neither side was willing to concede on the matter of maritime borders.

    Teacher's tip

    This sense is archaic and mostly found in historical literature; modern speakers use 'negotiations' instead.

  3. 03 C2 Proficiency FormalArchaic Law

    v.to enter into a formal agreement with another group or country.

    v.to enter into or negotiate a formal treaty; used transitively to describe reaching a state through such an agreement.

    Simple

    The tribes attempted to treaty with the settlers to protect their land.

    In context

    The warring factions eventually sought to treaty themselves into a lasting alliance against the common enemy.

    Usage

    Usually functions as an intransitive verb followed by 'with'.

Problems will inevitably emerge when a new treaty is put into practice.

The Guardian· 14 Aug 2026

A new draft text of the treaty was published earlier this week, which Cordano described as “an informal, evolving reference document”.

The Guardian· 13 Aug 2026

The noun is derived from Middle English trete, trety (“bargaining, negotiation; discussion; conference, meeting; entreaty, persuasion; agreement, contract, covenant; arrangement, settlement; agreement between two rulers, states, etc.; written work on a particular subject, treatise; subdivision of a written work, section”) [and other forms], from Anglo-Norman treté, traité, treaté, and Old French traité, traitié [and other forms] (modern French traité (“agreement between two rulers, states, etc.; treatise”)); traité or traitié is: * a noun use of the past participle of traiter (“to treat; to deal with, handle”), from Latin tractāre, the present active infinitive of tractō (“to drag, haul, tug; to handle, manage; to debate, discuss; to exercise, practise; to perform, transact”), from trahō (“to drag, pull”) + -tō (frequentative suffix); and * also from Latin tractātum (“written work on a particular subject, treatise”), from Latin tractātus (“dragged, hauled, tugged; handled, managed; exercised, practised; performed, transacted”), the perfect passive participle of tractō (see above). The verb is derived from the noun.

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

This entry
Origin Latin tractātus
Level C1 · Advanced
Frequency Common
Updated