Google has a detailed post up about how they treat synonyms and stemmed words in web search, and about the complications of having algorithms figure out just what is the right synonym in which context. They say one change to how results are displayed is that now, synonyms are bolded, too. For instance, in a search for pictures developed with coffee, Google considers the word “photos” to be synonymous to “pictures” and bolds it. You can also search for pictures developed with coffee -pictures to see just the “photos” results; also, you can use +pictures developed with coffee to turn off the synonyms for the word “pictures”.