signatory

American  

[sig-nuh-tawr-ee, -tohr-ee] / ˈsɪg nəˌtɔr i, -ˌtoʊr i /

adjective

1. having signed, or joined in signing, a document.

   the signatory powers to a treaty.

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noun

signatories plural

1. a signer, or one of the signers, of a document.

   France and Holland were among the signatories of the treaty.

signatory British  

/ ˈsɪɡnətərɪ, -trɪ /

noun

1. a person who has signed a document such as a treaty or contract or an organization, state, etc, on whose behalf such a document has been signed

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adjective

1. having signed a document, treaty, etc

Other Word Forms

Derived Forms

• nonsignatory
  adjective

Inflected Forms

noun

• signatories
  plural

Etymology

Origin of signatory

1640–50, in earlier sense “used in affixing seals”; 1860–65 signatory for def. 2; < Latin signātōrius of, belonging to sealing, equivalent to signā ( re ) to mark, seal ( see sign) + -tōrius -tory ¹

Explanation

A signatory is someone who signs a document and is subject to it. The co-signer for a loan is one type of signatory. A signatory is someone who signs a contract, therefore creating a legal obligation. There could be several signatories for a specific contract. Over time, this word has often been used for a person or country who signs a peace treaty. If the treaty is broken, the signatory will be blamed. You could be a signatory for a marriage, mortgage, adoption, lawsuit, or employment contract.

Example Sentences

Watchmen and Lost co-creator Damon Lindelof, a signatory who has an overall deal with Warner Bros Discovery, further voiced his opposition on social media.

From BBC • Apr. 13, 2026

Iran is also a signatory to the Nuclear Non-Proliferation Treaty, which makes the same pledge.

From Slate • Feb. 27, 2026

"People were saying: 'Well, kids are getting more anxious. There must be a reason -- let's ban social media'," argued one signatory, Axel Bruns, a digital media professor at Queensland University of Technology.

From Barron's • Dec. 1, 2025

Around that time, both Kahn and Indyke had signatory authority on some accounts.

From The Wall Street Journal • Nov. 23, 2025

On the morning of March 7, thirty thousand German troops had rolled into the demilitarized Rhineland, in open defiance of both the Treaty of Versailles and the Locarno Pact to which Germany was a signatory.

From "The Boys in the Boat: Nine Americans and Their Epic Quest for Gold at the 1936 Berlin Olympics" by Daniel James Brown

Related Words

• autograph
• identification
• ink
• name
• seal
• stamp
• trademark