impede vs propagate

impede

verb
  • To get in the way of; to hinder. 

propagate

verb
  • To cause to spread to extend; to impel or continue forward in space. 

  • To cause to take effect on all relevant devices in a network. 

  • To spread from person to person; to extend the knowledge of; to originate and spread; to carry from place to place; to disseminate. 

  • To produce young; to be produced or multiplied by generation, or by new shoots or plants. 

  • To cause to continue or multiply by generation, or successive production. 

  • To generate; to produce. 

  • To take effect on all relevant devices in a network. 

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