A synonym is a replacement term sequence that represents the same or a very similar thing as another term sequence. Search engines commonly implement synonym lists to connect different expressions used for similar concepts. section 2.4
Alternative labels form the most obvious subset of synonym lists, including initialisms, acronyms, misspellings, and alternative spellings. Synonyms can also include highly related phrases and map to entries in taxonomies, while taxonomies, ontologies, and knowledge graphs model broader classifications and relationships. section 2.4
Equivalent or closely related terms
Examples include human → homo sapiens or mankind, and software engineer ↔ software developer. The appropriate mapping depends on whether the terms represent the same thing or are treated as highly related in the search domain. section 2.4
