backed vs retracted

backed

adj
  • Having specified type of back. 

  • Having specified type of backing. 

retracted

adj
  • Couped by a line diagonal to the main direction. 

  • Withdrawn back and in, as the claws of a cat. 

  • Pronounced further back in the vocal tract. 

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