dilate vs thicken

dilate

verb
  • To enlarge; to make bigger. 

  • To speak largely and copiously; to dwell in narration; to enlarge; with "on" or "upon". 

  • To use a dilator to widen (something, such as a vagina). 

  • To become wider or larger; to expand. 

thicken

verb
  • To become thicker (in the sense of wider). 

  • To become thicker (in the sense of more viscous). 

  • To make thicker (in the sense of more viscous). 

  • To make thicker (in the sense of wider). 

  • To make more frequent. 

  • To strengthen; to confirm. 

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