ENGLISH
REFERENCE

ally

n. · v.
US //ˈæɫaɪ// al·ly
  1. 1 political/military partner (n.)
    B2 Upper Intermediate

    a country or group that has joined with another for a common purpose, like winning a war.

    a state formally cooperating with another for a military or political purpose, typically by treaty.

    Example

    The two countries have been close allies for over fifty years.

    Example

    The prime minister sought to reassure his European allies that the treaty obligations would be met despite the domestic political pressure.

  2. 2 personal/social supporter (n.)
    B2 Upper Intermediate

    someone who helps and supports you, especially when others are against you.

    a person who cooperates with or helps another; often used in social justice contexts to describe a supporter of a marginalised group.

    Example

    She was a strong ally during the office dispute and defended my ideas.

    Example

    The organisation provides training for people who want to be better allies to the LGBTQ+ community in the workplace.

Show 1 more senseShow fewer
  1. 3 to join forces (v.)
    C1 Advanced Formal

    to join with another person or group to work together.

    to combine or unite for a specific purpose; often used reflexively with 'with' or 'to'.

    Example

    The small company decided to ally with a larger firm to survive the crisis.

    Example

    The minor political party chose to ally itself with the opposition in a desperate attempt to block the controversial legislation.

    Usage

    Often used in the passive voice or reflexively as 'to ally oneself with'.

Etymology 1

From Middle English allien, alien (“to form an alliance, associate, join; to become an ally; to introduce (someone) as an ally; to marry; to become related (to someone); to attack, engage in combat; to combine; (cooking) to combine ingredients, especially to bind them together”) [and other forms], from Anglo-Norman alier, allier, Middle French alier, allier [and other forms], and Old French alier (“to join together, unite; to alloy (metals); (cooking) to combine ingredients”) (modern French allier), from Latin alligāre, the present active infinitive of alligō, adligō (“to bind around, to, or up (something), bandage, fasten, fetter, tie; to hold fast; to detain, hinder”), from al-, ad- (intensifying prefix) + ligō (“to bind, tie; to bandage, wrap around; to unite”) (from Proto-Indo-European *leyǵ- (“to bind, tie”)). Doublet of allay, alligate, alloy, and ligament.

Etymology 2

From Middle English allie, alie [and other forms], probably partly: * from allien (verb): see etymology 1; and * from Anglo-Norman allié, alié, alyé, allyé, Middle French allié, alié, allyé (“associate, supporter; friend; relative; person, state, etc., associated or united with another by alliance or treaty”), and Old French alliiet (“military or political ally”) (modern French allié), a noun use of the past participle of Anglo-Norman alier, allier, Middle French alier, allier, and Old French alier (verb): see etymology 1.

Etymology 3

See alley.

Word family

© 2026 English Reference