Some similar terms should be indexed into the search engine. Even terms that are only similar in context. Does not need to be NLP-driven semantic mapping, just a simple rules-based thesaurus.
For instance, in the attached example, I have wage data showing "Hourly Rate" and "Yearly Rate". When I search "salary" I get no results, even though "Hourly Rate" and "Yearly Rate" are both categorized as "Currency". Even though these texts are not identical, searching for "salary" should at the very least pull up any data that is in the Currency categorization imho.