out- vs retro-

out-

prefix
  • Toward the outside of, away from 

  • External to, on the outside of 

  • Forms verbs with the sense of surpassing or exceeding the prefixed word. This construction is productive. 

  • Greater than 

  • Completely 

  • Beyond 

retro-

prefix
  • In the opposite direction. 

  • Behind. 

  • Back or backward. 

  • Pertaining to an earlier time. 

  • Old-fashioned or old school. 

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