I think you're going to find those results somewhat true in general. If I search for "experience" I get definitions near the top of my search results. If I search for "Catholicism", however, I get very different results, with far more information ABOUT it than definitions OF it.
Google's ranks are going to be based on what most people are really looking for when they type in a search word. When someone types in "experience", they probably want to know what it means. When they type in "books" they're probably shopping. The search results reflect that.
So, with that in mind, look at the words that point to your dictionary versus those that don't, and ask yourself what someone typing that word probably wants. If it's not a definition, you're probably NEVER going to rank high for that word.