brighten vs stain

brighten

verb
  • To make bright or brighter in color. 

  • To make illustrious, or more distinguished; to add luster or splendor to 

  • To make more cheerful and pleasant; to enliven 

  • To grow bright, or more bright in color; to clear up 

  • To become brighter or more cheerful in mood 

stain

verb
  • To treat (a microscopic specimen) with a dye, especially one that dyes specific features 

  • To cause to seem inferior or soiled by comparison. 

  • To coat a surface with a stain 

  • To taint or tarnish someone's character or reputation 

  • To discolour. 

  • To become stained; to take a stain. 

noun
  • A reagent or dye used to stain microscope specimens so as to make some structures visible. 

  • A discoloured spot or area. 

  • Any of a number of non-standard tinctures used in modern heraldry. 

  • A blemish on one's character or reputation. 

  • A substance used to soak into a surface and colour it. 

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