"Merriam-Webster's New Dictionary of Synonyms" is devoted to explaining shades of meaning among synonyms. For example, it explains why you might choose to use d

"Merriam-Webster's New Dictionary of Synonyms" is devoted to explaining shades of meaning among synonyms. For example, it explains why you might choose to use defer, postpone, intermit, suspend, or stay. Interesting if you're a writer, or if you're generally interested in suggestion, implication, and denotation. It's very browsable.