Single ideas may be expressed in many different ways. WordStat provides several tools to help you identify instances of different ideas. This includes tools such as the Suggest feature that can be used to retrieve a list of all known synonyms, related words and inflected forms of the items already in a dictionary from another source such as a thesaurus or a lexical database. The Auto-Suggest feature is an optional panel on the Frequencies page that also lists suggestions.
For written instructions: See manual pages 118-119