There was a series of number ranges that mapped onto other ranges. The simple approach was filling dictionaries, which worked well for the example data. In the actual data, there ranges were much much larger (in the 100,000,000's), which made the dictionaries prohibitively large.
If you don't know the meaning of a word, you can literally Google "{The word you don't know} definition." Google.com is a really handy and easily-accessed dictionary.