denote vs signalize

denote

verb
  • To indicate; to mark. 

  • To make overt. 

  • To refer to literally; to convey as meaning. 

signalize

verb
  • To indicate; to be a sign of. 

  • To furnish (a traffic intersection) with a traffic signal. 

  • To communicate with (someone) by means of a signal. 

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