commendation vs knock

commendation

noun
  • That which is the ground of approbation or praise. 

  • The act of commending; praise; favorable representation in words; recommendation. 

  • A message of affection or respect; compliments; greeting. 

  • An award or recognition for performance; a medal. 

knock

noun
  • A criticism. 

  • An abrupt rapping sound, as from an impact of a hard object against wood. 

  • A sharp impact. 

  • A batsman's innings. 

  • A blow or setback. 

  • Preignition, a type of abnormal combustion occurring in spark ignition engines caused by self-ignition; also, the characteristic knocking sound associated with it. 

  • Synonym of hunger knock 

verb
  • To criticize verbally; to denigrate; to undervalue. 

  • To kick a ball towards another player; to pass. 

  • To rap one's knuckles against something, especially wood. 

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