- A software tool included with some word processors that provides synonyms for selected words on command. Users using Microsoft Word can open a thesaurus by highlighting the word the wish to look up and pressing the shortcut key Shift+F7.
- A book, software program, or online service that provides alternative or similar words to the word being searched for.
- Popular online thesaurus services include: Thesaurus.com and Merriam-Webster Online.
- An example a free downloadable Thesaurus for Windows is WordWeb.