The Southern Reach series by Jeff Vandermeer (Annihilation, etc.):
Terroir: 37 times
Banal: 20 times
Mote (as in dust mote): 11 times
Somewhat rarely used words that I would have overlooked a couple instances of, but just so heavily used in these books that it was laughable.
Superb book, and the sequels are pretty good too. Something I doubt is said very often but, I think the 4th book in the series was the strongest, at least of the sequels. Some very important themes; he is a great author.