[ verb uh-lahy; noun al-ahy, uh-lahy ]
See synonyms for: allyalliedalliesallying on

verb (used with object),al·lied, al·ly·ing.
  1. to unite formally, as by treaty, league, marriage, or the like (usually followed by with or to): Russia allied itself to France.

  2. to associate or connect by some mutual relationship, as resemblance or friendship.

verb (used without object),al·lied, al·ly·ing.
  1. to enter into analliance; join; unite.

noun,plural al·lies.
  1. a person, group, or nation that is associated with another or others for some common cause or purpose: Canada and the United States were allies in World War II.

  2. Biology. a plant, animal, or other organism bearing an evolutionary relationship to another, often as a member of the same family: The squash is an ally of the watermelon.

  1. a person who associates or cooperates with another; supporter.

  2. a person who advocates for or supports a marginalized or politicized group but is not a member of the group: Straight allies speak up for the LGBTQ community.As a man, how can I be a good ally to women in the struggle for gender equality?

Origin of ally

First recorded in 1250–1300; Middle English alien, from Anglo-French alal(l)ierier, aillaier, Old French alier, from Latin alligāre “to bind to”; see alloy

Other words for ally

Opposites for ally

Other words from ally

  • al·li·a·ble, adjective
  • pre·al·ly, noun, plural pre·al·lies.
  • pre·al·ly, verb, pre·al·lied, pre·al·ly·ing.

Words that may be confused with ally

Words Nearby ally

Other definitions for -ally (2 of 2)


  1. an adverbial suffix attached to certain adjectives with stems in -ic that have no forms ending in -ical: terrifically.

Origin of -ally

2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use ally in a sentence

British Dictionary definitions for ally


verb(əˈlaɪ) -lies, -lying or -lied (usually foll by to or with)
  1. to unite or be united, esp formally, as by treaty, confederation, or marriage

  2. (tr; usually passive) to connect or be related, as through being similar or compatible

noun(ˈælaɪ, əˈlaɪ) plural -lies
  1. a country, person, or group allied with another

  2. a plant, animal, substance, etc, closely related to another in characteristics or form

Origin of ally

C14: from Old French alier to join, from Latin alligāre to bind to, from ligāre to bind

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012