You can check the "store search terms for which no search results were found" in Shopify's store analytics report. If they really don't exist, there's nothing you can do about it, but in many cases you can find them with other words, so it's a good idea to set up synonyms using Search & Discovery.
The "Top online store searches with no results" section of the Store Analytics report shows the actual search terms that were searched but didn't return any results.
[How to avoid zero search results] If a different word would produce search results, set synonyms in Search & Discovery.
[Example of avoiding zero search results] Search results can be obtained by grouping words that did not return search results in hiragana.
