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.
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.
a person who associates or cooperates with another; supporter.
a person who advocates for or supports a marginalized or politicized group but is not a member of the group: As a man, how can I be a good ally to women in the struggle for gender equality?
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?
to unite or be united, esp formally, as by treaty, confederation, or marriage
(tr; usually passive) to connect or be related, as through being similar or compatible
a country, person, or group allied with another
a plant, animal, substance, etc, closely related to another in characteristics or form
What else does ally mean? An ally is someone that aligns with and supports a cause with another individual or group of people. A straight ally, more specifically, is an individual outside of the LGBTQ community that supports their fight for equality and rights.
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
If you have an ally, you have someone who is on your side, like a more experienced teammate who is your ally in convincing the coach to give you more playing time. Ally comes from the Latin word alligare, meaning "to bind to," like nations who are allies in wartime — they will act together, and protect one another. You can also use ally as a verb, meaning "join forces with." For example, you might ally yourself with influential people to advance your career. As a noun, pronounce ally like this: "AL-eye." As a verb, it's "uh-LIE."
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His character, Luther, is a key ally of Cruise’s Ethan Hunt and played a crucial role in the events of 2025’s “Mission: Impossible — The Final Reckoning.”
From Los Angeles Times • Apr. 30, 2026
Rocha is also seen as a close ally of former Mexican President Andrés Manuel López Obrador, Sheinbaum’s mentor and predecessor.
From The Wall Street Journal • Apr. 29, 2026
Moss said he considers Abdul to be an ally and friend: “We talk. We text. That’s the only way we move forward.”
From Slate • Apr. 29, 2026
They follow a pledge by leader Kim Jong Un to bolster nuclear forces, as Pyongyang reaps the benefits of deeper ties with Russia and sharpens its invective against US ally South Korea.
From Barron's • Apr. 27, 2026
Jinx placed the money on the bar and took a seat behind the counter next to Shady, his one sure ally in the room.
From "Moon Over Manifest" by Clare Vanderpool
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.