old fellow vs pisser

old fellow

noun
  • Synonym of old chap (“the penis”) 

pisser

noun
  • Synonym of piss clam 

  • That which pisses, particularly a penis. 

  • A disappointing or frustrating situation or event. 

  • A pub. 

  • A toilet or urinal. 

  • An extremely amusing person or thing. 

  • One who pisses. 

  • Someone or something impressive or remarkable. 

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