“Returning zero results for a search query is one of the fastest ways to frustrate & lose potential customers, and is akin to accidentally forgetting to turn around the "Closed" sign on your storefront” says Google. Google Commerce Search has always arrived "out of the box" with best automatic stemming, spelling, and synonym technology available; “now it's become easier for retailers with unusual or distinct product catalogs to upload and manage custom synonym dictionaries and trigger search expansion, so that the query as typed automatically triggers results for synonymous products.
To add synonyms, simply log into control panel and add or delete search terms you want to trigger the synonym expansion, or you can create an XML file and quickly upload that to your account. Google already has a large body of synonym data for general search terms, and since Google Commerce Search lets you harness many of search features of Google.com, you shouldn't bother replicating work. Instead, focus on adding synonyms for queries specific to your product line or online store,” notes Google.