words that authors set on Repeat

Full-length books are certain to contain repetitive words. Some of those repetitions are more noticeable than others.

• In The Beginning of Infinity by David Deutsch, one of those words is "parochial". 
• In Darth Plagueis by James Luceno, one of those words is "rock" as a verb, which refers to a head motion, often from side to side. Are you ready to rock? Your head?