Spotlight has reserved words. One of those is kind. So I am saying restrict this Spotlight search to documents whose kind is Word (e.g. doc/docx) and find that quoted string in only that category of Word documents.
See: Narrow your search results on Mac - Apple Support
Simply entering a string without narrowing the search, or not having the right Spotlight category selected may not find anything, or everything that you don't want to see.
Verify that in your System Settings : Siri & Spotlight panel that you have selected the Documents Search Results category. If you haven't done so, do it now. Then click the Spotlight Privacy… button, and on that Privacy panel, drag and drop your Macintosh HD Desktop icon onto that window, wait ten seconds, select it, and click the [-] button to remove it. This will trigger a Spotlight indexing of your drive and this time, the Word documents will get indexed. Then my command examples will work on your Word documents.