The ideal guide to choosing the right word. Entries go beyond the word lists of a thesaurus, explaining important differences between synonyms. Provides over 17,000 usage examples. Lists antonyms and related words.
It is important to understand that this book is NOT a thesaurus, but a completely different, yet equally useful, reference work. A very good essay at the beginning of this book explains this, and gives an interesting history of how books of synonyms developed over the past centuries.
The best thesaurus is Roget's International Thesaurus -- the original work, now in its 6th edition, not one of the ones in "dictionary format." Roget's provides long lists words of similar meaning, grouped under conceptual headings. Its purpose is to jog your memory, spur creative thinking, or help you realize what you are really trying to say. It is absolutely the best thing for easing writer's block and helping you to find a word.
The purpose of this book, on the other hand, is to help you understand the differences between similar words. It explains nuances of meaning and compares words that mean approximately, but not quite, the same thing. It has a number of long entries that discuss 5 or 6 similar words together, explaining when to use each and giving examples (usually from good literature) of the correct use of each. When you look up one of the other synonyms, it will point you to the main article in which it is discussed. For example, the entry for "prim" dicusses and differentiates the near-synonyms "priggish, prissy, prudish, puritanical, and straitlaced." It explains the differences in meaning, and the contexts in which each word is appropriate. If you look up any one of those words, it will list the synonyms briefly but refer you to the main discussion under "prim."
I highly recommend this book to high school, college, and graduate students; to people learning English; and to people who write for a living. I suggest that a writer get this book and Roget's International Thesaurus (as well as a good dictionary, of course). Look up a word in Roget's to find some synonyms, then look them up in the Merriam-Webster's Dictionary of Synonyms to see which of those words are really correct in the context.
It's also in some ways easier to use than a typical thesaurus, since if you just need a different word and can't recall one, it's easiest to just look it up and get a quick alternative, instead of going through all the extra words you'd get in a thesaurus, but which aren't exactly what you want. Overall, a fine reference work and one that deserves to be better known.