This site allows you to see detailed information on academic words in English, based on data in 120 million words of academic texts in the the Corpus of Contemporary American English (COCA).
You can see the overall frequency for each word in academic English, as well as the frequency of words in different kinds of academic genres -- business, medicine, law, science and technology, humanities, and so on. For each word you can also find the 20-30 most frequent collocates (nearby words) in academic texts and see 200 or more concordance lines (words in context). You can also see a list of synonyms and (from WordNet) words with more specific and more general meanings, and in all of these cases you can click to see the entries for those related words as well.
If this is your first time here, you'll probably want to spend 1-2 minutes looking at the Guided Tour. If you've used COCA before, you might want to look at the comparison of the two resources. You might also want to consider downloading the data for offline use.