ab vs sit-up

ab

noun
  • abdominal muscle. 

  • An abscess caused by injecting an illegal drug, usually heroin. 

  • The early stages of; the beginning process; the start. 

verb
  • To abseil. 

sit-up

noun
  • An exercise in which the abdominal muscles are contracted, bringing the torso of a person lying down to a more upright position. 

How often have the words ab and sit-up occurred in a corpus of books? (source: Google Ngram Viewer )