knobhead vs wanker

knobhead

noun
  • A fool; an idiot; a contemptible person. 

  • The glans penis 

wanker

noun
  • An idiot, a stupid person. 

  • Someone who shows off too much, a poser or poseur; someone who is overly self-satisfied. 

  • A penis. 

  • An annoying person. 

  • An ineffectual person. 

  • A very informal address used between friends. 

  • A person who wanks. 

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