What's another word for "thesauri?"

Hypertext edition of Roget’s Thesaurus, based on the 1911 edition from Project Gutenberg.

Online version of Roget’s New Millennium Thesaurus. Each entry includes a brief definition, synonyms, and antonyms (where appropriate).

A lexical database that provides synonyms and other related words of English language words. Created by the Cognitive Science Laboratory of Princeton University.