In Jean-Luc Godard’s The New World, you could pick up a dictionary and not find words you knew existed. The government would keep publishing updated versions of the dictionary without words which it deemed unsuitable for use, knowing that people would gradually forget them.
It is quite a different matter that, in reality, the Oxford dictionary is updated frequently, bringing new words within its folds as the English language evolves and grows.
Google Ngram is an extraction tool, which, on the face of it, is a boring graph: Type in a word and it shows you its usage in published works between the years 1800 and 2000. You could then proceed to search for snippets of books where these words have been used by using Google Books.