darken vs put on

darken

verb
  • To become gloomy, darker in mood. 

  • To render gloomy, darker in mood. 

  • To cloud, obscure, or perplex; to render less clear or intelligible. 

  • To become dark or darker (having less light). 

  • To make dark or darker by reducing light. 

  • To make dark or darker in colour. 

  • To blind, impair the eyesight. 

  • To become dark or darker in colour. 

  • To be blinded, lose one’s eyesight. 

  • To make foul; to sully; to tarnish. 

  • To get dark (referring to the sky, either in the evening or as a result of cloud). 

put on

verb
  • To assume, adopt or affect; to behave in a particular way as a pretense. 

  • To don (clothing, equipment, or the like). 

  • To initiate cooking or warming, especially on a stovetop. 

  • To perform for an audience. 

  • To organize a performance for an audience. 

  • To fool, kid, deceive. 

  • Used other than figuratively or idiomatically: see put, on. 

  • To bet on. 

  • To play (a recording). 

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