How to implement DefinedTerm Schema: The Implementation Guide
Schema.org/DefinedTerm is the structured data type that tells search engines and language models: “this page is the authoritative definition of a named concept, created by a specific entity, and part of a defined terminology set.” It is the most important schema type for knowledge positioning in pre-consensus territory.
Required properties
@type: “DefinedTerm” — must be explicit, not inherited.
@id: The canonical URL of the definition page. This is the stable identifier by which the knowledge graph will reference this entity in perpetuity. Use the full URL with trailing slash if that is your canonical form.
name: The exact term being defined. Use the same string consistently across all pages that reference this concept. Variation in the name string weakens entity association.
description: The definition in 1–3 sentences. This is the text that language models will extract and cite. Write it as a self-contained, unambiguous definition — not as an introduction to a longer article.
inDefinedTermSet: Reference to the /glossary/ page, marked as a DefinedTermSet. This property establishes that this term is part of an organized terminology framework, not an isolated definition.
termCode: A stable, unique code for this concept within your term set. Use a consistent format (e.g., “IG-001” for the first term in the Ignorance Graph set). This code provides disambiguation when the term name is similar to other concepts.
Recommended properties
sameAs: URLs of external sources that confirm the entity — Wikidata Q-ID, Wikipedia page, authoritative third-party definition. Add these only when real external sources exist. Do not use placeholder values.
url: The canonical URL, identical to @id.
The DefinedTermSet on /glossary/
The /glossary/ page must carry DefinedTermSet schema with: @type: “DefinedTermSet”, name: (the name of your terminology framework), url: the glossary URL, hasPart: an array of @id references to all DefinedTerm pages in the set.
The DefinedTermSet is what tells the knowledge graph that all terms on this site are part of a coherent, authored framework — not a collection of isolated definitions. This property significantly strengthens entity association for all terms in the set.
Implementation note
Deploy all DefinedTerm schema as JSON-LD in the section, not as microdata inline. JSON-LD is the recommended format for all structured data by Google and is easier to audit and maintain.