encode vs keyword

encode

noun
  • An encoding operation. 

verb
  • To constitute the code necessary for the biosynthesis of a protein by means of a matrix so as to transcribe DNA material. 

  • To convert source information into another form. 

  • To convert (plain text) into code. 

keyword

noun
  • Any word used as the key to a code. 

  • A reserved word used to identify a specific command, function, etc. 

  • Any important word in a text or document, which may be linked to other words or other information, or at least merely listed in the metadata for searches to find. 

  • Any word that occurs in a text more often than normal. 

  • Any word used in a reference work to link to other words or other information. 

verb
  • To tag with keywords, as for example to facilitate searching. 

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