jigging vs slipping

jigging

noun
  • The act of dancing a jig. 

  • The act of using a jig; the act of separating ore with a jigger, or wire-bottomed sieve, which is moved up and down in water. 

slipping

noun
  • The act of something that slips; a slip; a skidding or sudden loosening motion. 

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