Search for the root words using root words with prefixes or suffixes
What you're talking about is "stemming" where a word -- refill -- is related to its "root" or "stem" word -- fill. This is usually implemented through Full Text Search, which I believe SQLite supports, though I've never used it.

To implement this yourself in your own tables and code will be a complex task requiring a thorough understanding of the target language(s), how word-forms are constructed and how the grammar is defined, both theoretically and in practice.