I like the term "search database", since it's a database that has some APIs and logic purpose-built for general search engines built on top of it. Elasticsearch

I like the term "search database", since it's a database that has some APIs and logic purpose-built for general search engines built on top of it. Elasticsearch, for example, is frequently used as a document-oriented data store rather than a search engine, like in the case of Kibana or APM.