grow vs tone down

grow

verb
  • To appear or sprout. 

  • To become larger, to increase in magnitude. 

  • To undergo growth; to be present (somewhere) 

  • To develop, to mature. 

  • To cause or allow something to become bigger, especially to cultivate plants. 

  • To assume a condition or quality over time. 

tone down

verb
  • To moderate or relax; to diminish or weaken the striking characteristics of; to soften. 

  • To make a television program, piece of writing, etc. less offensive and so more suitable for a family audience. 

  • To relax; to make quieter or less obtrusive; to make milder. 

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