comment vs knock

comment

noun
  • A spoken or written remark. 

  • A remark embedded in source code in such a way that it will be ignored by the compiler or interpreter, typically to help people to understand the code. 

  • The part of a sentence that provides new information regarding the current theme. 

  • The act of commenting. 

verb
  • To make remarks or notes. 

  • To insert comments into (source code). 

  • To comment out (code); to disable by converting into a comment. 

  • To remark. 

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 comment and knock occurred in a corpus of books? (source: Google Ngram Viewer )