WAG vs misconjecture

WAG

noun
  • A wife or girlfriend of a sports star or other celebrity, originally and especially of an association football player. 

  • A wild-assed guess; a rough estimate. 

misconjecture

noun
  • A wrong conjecture or guess. 

verb
  • To conjecture wrongly. 

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