plaw vs swelter

plaw

noun
  • A boiling. 

verb
  • To boil; seethe. 

  • To boil; boil slightly; parboil. 

swelter

noun
  • Intense heat. 

verb
  • To perspire greatly from heat. 

  • To cause to faint, to overpower, as with heat. 

  • To suffer terribly from intense heat. 

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