arse vs whosit

arse

noun
  • Used in similes to express something bad or unpleasant. 

  • A stupid, pompous, arrogant, mean or despicable person. 

  • A person; the self; (reflexively) oneself or one's person, chiefly their body; (by extension) one's personal safety, or figuratively one's job, prospects, etc. 

verb
  • To be silly, act stupid or mess around. 

whosit

noun
  • A thing (used in a vague way to refer to something whose name one cannot recall or is embarrassed to say) 

  • A specific person (used in a vague way to refer to someone whose name one cannot recall) 

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