suppress vs tamp down

suppress

verb
  • To exclude undesirable thoughts from one's mind. 

  • To forbid the use of evidence at trial because it is improper or was improperly obtained. 

  • To put an end to, especially with force, to crush, do away with; to prohibit, subdue. 

  • To restrain or repress, such as laughter or an expression. 

  • To prevent publication. 

  • To stop or prevent the enemy from executing unwanted activities like firing, regrouping, observation or others. 

  • To stop a flow or stream. 

  • To reduce unwanted frequencies in a signal. 

tamp down

verb
  • To suppress (something, usually an emotion or thought). 

  • To compact a substance (usually soil) until it is flat. 

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