Integration of Wolfram Alpha's dictionary would be useful when looking for words'/terms' definitions and synonyms/antonyms. This would operate much like Google's current featuring of Oxford Dictionary results in an integrated widget. See comparison below.
A similar definition/synonym widget utilising Wolfram Alpha integration would save me a non-negligible amount of time clicking through to dictionaries' links etc. A variety of buttons (like on Google) where I can cycle through the dictionary and thesaurus, as well as pronunciation and usage examples, for a particular word or term would be useful too.
This should work for a number of search permutations too: e.g. definition of [word/term]; [word/term] definition; definition [word/term] — and the same for synonyms.