DefinedTerm Schema

DefinedTerm schema is a specific structured-data type from schema.org, the shared vocabulary that lets websites label their content so machines can understand it. The DefinedTerm type describes exactly what it sounds like — a defined term and its definition — with properties for the term's name, its description (the definition), and often a term code and its membership in a DefinedTermSet, the collection the term belongs to, such as a glossary. Marked up as JSON-LD in the page's code, it tells a search engine or an AI system, in a structured way, that this page defines this term and here is the definition, rather than leaving the machine to infer that from prose alone. It is the schema built for glossaries, dictionaries, taxonomies, and any content whose purpose is to define terms.

DefinedTerm schema matters because search and AI increasingly reward content a machine can parse confidently. Structured data does not change what a human reads, but it removes ambiguity for the machine, which can improve how the page is understood, cited, and surfaced — in rich results, in knowledge panels, and increasingly in the answers that AI answer engines assemble. For a glossary specifically, DefinedTerm is the semantically correct type. It declares that the page's job is to define a term. That precision matters for answer engine optimization, where the goal is to be the source an AI trusts and cites for a definition. Using the type that literally means defined term gives that content the clearest possible machine-readable claim to being the definition of the thing.

The most common confusion is between DefinedTerm schema and Article schema, and the right choice follows the content's purpose. Article schema, and its cousins NewsArticle and BlogPosting, describes a piece of writing — a headline, author, publish date, body — and suits blog posts, news, and editorial content. DefinedTerm schema describes a term and its meaning, and suits a glossary entry whose whole job is to define something. A glossary page marked up as an Article tells the machine this is an article, which is true but vague. Marked up as a DefinedTerm, it tells the machine this defines this term, which is precise. The schema should match what the content is, and a definition page is not an article about a topic — it is a definition of a term.

The choice ripples into how machines treat the page. FAQPage schema marks up question-and-answer pairs, HowTo marks up steps, Product marks up items for sale, and DefinedTerm marks up definitions. Picking the wrong type either wastes the opportunity, as with an untyped or generically typed definition, or misrepresents the content, as with a definition dressed up as something it is not, which search engines increasingly detect and discount. Schema can also be combined thoughtfully — a glossary term can carry DefinedTerm markup while an FAQ section on the same page carries FAQPage markup — but the core of a definition page should be DefinedTerm because that is what the page fundamentally is. Matching the type to the truth of the content is the whole discipline of structured data.

Using DefinedTerm schema well means marking up genuine definition pages with accurate JSON-LD: the term's name, a clear description that matches the visible definition, and membership in a DefinedTermSet that represents the glossary. Keep the structured data honest. It must describe what is actually on the page, because schema that contradicts the visible content is a cloaking signal that search engines penalize rather than reward. Validate the markup with a structured-data testing tool so errors do not silently break it. Combine it sensibly with other appropriate types on the page, such as an FAQ block or breadcrumb navigation, and keep the definition itself genuinely useful, because schema amplifies good content but cannot rescue thin or wrong content.

The failures are marking up a definition as an Article or leaving it untyped, which wastes the semantic precision DefinedTerm offers; writing schema that does not match the visible page, which reads as manipulation; neglecting to validate, so broken markup goes unnoticed; and treating schema as a ranking trick rather than a way to communicate meaning clearly. Structured data is not a shortcut to visibility. It is a way to make already-useful content unambiguous to machines. The discipline is to use DefinedTerm for what it means — genuine defined terms — mark them up accurately and honestly, validate them, and pair them with content strong enough to deserve the citation the markup helps it earn.

DefinedTerm schema — named for the schema.org DefinedTerm type, itself from define, Latin definire, to set bounds — marks up a term and its definition for machines.

Etymology: source.

Search interest for this term over the last five years:

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Areas of marketing where definedterm schema is a core concern: