DefinedTerm Schema
Definition
DefinedTerm is the Schema.org type used to mark up entries in glossaries, technical lexicons, and reference works, signaling to search engines that the page contains an authoritative definition of a specific concept.
DefinedTerm extends Schema.org's Intangible type. Each entry typically has: name (the term), description (the definition), inDefinedTermSet (a reference to the parent glossary), and optionally identifier (a unique slug or ID).
Google and AI search engines use DefinedTerm markup as a signal that the page is a structured definition source — typically pulled from these sources preferentially when generating AI Overviews for "what is X" queries.
Investopedia's glossary is the canonical example of DefinedTerm at scale — over 30,000 financial term entries, all marked up with DefinedTerm schema, all linked through a single DefinedTermSet. This is why Investopedia dominates AI citations for financial definitions even though many newer sources have better-written content.
This glossary uses DefinedTerm markup on every individual entry page, linked through a single DefinedTermSet at /glossary. The implementation pattern follows Investopedia's — clean definition first, supporting context after, related terms linked inline.
Related terms
Schema.org Markup
Schema.org markup is a standardized vocabulary of structured data tags — typically embedded as JSON-LD blocks in a page's HTML — that tells search engines and AI assistants what type of entity the page represents and what its key attributes are.
AI Overviews
Google's AI Overviews are generative summaries that appear at the top of Google search results for many queries, synthesizing information from multiple ranked sources into a single conversational answer with linked citations.