gyratory vs rotatory

gyratory

adj
  • Moving in a circle, or spirally; revolving; whirling around. 

noun
  • A large traffic roundabout with non-standard lane markings or priorities, or with buildings on the central island. 

rotatory

adj
  • of, pertaining to, or causing rotation; rotational 

How often have the words gyratory and rotatory occurred in a corpus of books? (source: Google Ngram Viewer )