Synonyms are words with similar meanings, such as "notebook" and "laptop." In a search engine, synonym expansion can be performed at query time or index time. To apply a dictionary of synonyms to a portal's content, it is necessary to reindex using the Reindex Contents web service, or launch a reprocessing job in the Enrich and Clean interface. Synonym expansion at query time lets the search system administrator modify thesauri without needing to reindex. See Synonyms.