First posted on History Survey, which is no longer active.

The thesaurus is a useful tool, but it can also be dangerous. It is not enough to look for synonyms and assume that these words mean what you think they mean. If the word you found is unfamiliar, you must go the extra mile and look it up in a dictionary. Only then will you be in a position to decide whether you have chosen the right word or not.

Students of foreign languages learn a similar lesson. If you want to translate English into French, for example, it is not enough to look for a French word in the English-French dictionary. You also need to double-check that word in the French-English dictionary.

Fortunately, these days much of this work can be done electronically—if you have a reliable dictionary. Mac users can use the built-in dictionary and thesaurus application on their computers. (Use the application, not the widget.) What makes this dictionary so great is not simply that Apple makes it easy to use, but that is is based on the highly usable Oxford American Dictionary. Another tool for any operating system is Merriam-Webster online, which offers plugins for Firefox and Microsoft Explorer. While I have not tried the dictionary that comes with Microsoft Word, I have seen my teenage son get some pretty bad results with it in the past. Now he uses Apple’s built-in dictionary.

By the way, if you like online dictionaries, one interesting place to go is OneLook, which offers you results from a large number of dictionaries.

See also my books page.