thesaurus. The plurals “thesauruses” and “thesauri” occur with equal frequency. The homegrown “thesauruses” is probably better — e.g.: o “In addition, there are the computerized thesauruses included in most word-processing programs.” Leslie T. Sharpe & Irene Gunther, Editing Fact and Fiction 204 (1994). o “Thesauruses also increased in popularity, rising from 22nd in terms of numbers of adult purchasers in 1994, to 10th last year.” Debbie Davies, “Mapping Out the Best of the Books,” Independent, 31 May 1997, at 19. Language-Change Index — “thesauruses”: Stage 5. For information about the Language-Change Index click here. ——————– Quotation of the Day: “It is fun to play the game of synonyms. Young writers sometimes buy a thesaurus and revel in the riches that it offers. What they have yet to discover is that no two words have precisely the same meaning, and that the practical value of a book of synonyms lies mainly in saving time for a writer who already understands the distinctions but cannot on the instant call to mind the uniquely appropriate term.” Ellsworth Barnard, English for Everybody 84 (1979).