piddle vs relieve oneself

piddle

verb
  • To urinate. 

  • Often followed by about or around: to act or work ineffectually and wastefully. 

  • Synonym of nibble: to pick at or toy with one's food, to eat slowly or insubstantially. 

noun
  • A piss: an act of urination. 

  • Nonsense or a trivial matter. 

  • Piss: urine. 

relieve oneself

verb
  • To urinate or defecate. 

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