boner vs erect penis

boner

noun
  • An erect penis. 

  • An often perverse sense of enjoyment from or predilection towards something. 

  • Why do guys get boners when they wake up in the morning? 

  • One who or that which bones (removes bones). 

erect penis

noun
  • a penis that is engorged with blood 

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