churning vs rocking

churning

noun
  • The act by which something is churned. 

  • The quantity of butter prepared (by churning) at one time. 

rocking

noun
  • The motion of something that rocks. 

  • The abrading of a copper plate with a rocker, preparatory to mezzotinting. 

  • The motion by which the design on a steel mill is transferred to a copper cylinder. 

adj
  • Excellent; great. 

  • Shaking, swaying or moving back and forth. 

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