cubit vs elbow bump

cubit

noun
  • The distance from the elbow to the tip of the middle finger used as an informal unit of length. 

  • Any of various units of length approximating this distance, usually around 35–60 cm. 

elbow bump

noun
  • The touching of elbows between two people, sometimes as an alternative to a handshake, fist bump, or other form of contact when attempting to avoid the spread of germs. 

  • A hit to the elbow; also, an injury to the elbow caused by such a hit. 

  • A hit or jab made with the elbow. 

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