The more you read the more your vocabulary grows, or so the saying goes. I believe that, so much so that when I don't feel challenged or stretched by a book vocabularily (no, that really isn't a word - is it?!) frankly, I'm a bit disappointed. In fact, Swimming Home was disappointing to me in that regard - among others.
My disappointment drove me to go back to list I've made (haphazardly) over the years, of words I've learned or re-learned, thanks to some the books I've read.
From Iran Awakening there was restive and foment (and a dozen others, at least).
How Soccer Explains the World prompted me to look up obeisance, pogrom (a riot-like fight/Russian origin) picaresque, inveigh (speak of in a hostile way, I think) counter-hegemony, legerdemain, and soi-disant.
I'm sure I learned a few from the The Guernsey Literary and Potato Peel Pie Society,
but - well, did I mention the list was haphazard? That's about as far as I got.
What about you? Ever find yourself looking up new words as you read? Tell me about it.