equivoque vs spoonerism

equivoque

noun
  • A play on words, a pun. 

  • Ambiguity or double meaning. 

spoonerism

noun
  • A play on words on a phrase in which the initial (usually consonantal) sounds of two or more of the main words are transposed. 

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