dim vs lighten

dim

verb
  • To render dim, obscure, or dark; to make less bright or distinct 

  • To make something less bright. 

  • To deprive of distinct vision; to hinder from seeing clearly, either by dazzling or clouding the eyes; to darken the senses or understanding of. 

  • To become darker. 

adj
  • Not bright or colorful. 

  • Indistinct, hazy or unclear. 

  • Not smart or intelligent. 

  • Disapproving, unfavorable: rarely used outside the phrase take a dim view of. 

lighten

verb
  • To make brighter or clearer; to illuminate. 

  • To become light or lighter in weight. 

  • To become brighter or clearer; to brighten. 

  • To make less serious or more cheerful. 

  • To illuminate with knowledge; to enlighten. 

  • To descend; to light. 

  • To emit or disclose in, or as if in, lightning; to flash out, like lightning. 

  • To alleviate; to reduce the burden of. 

  • To become less serious or more cheerful. 

  • To make light or lighter in weight. 

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