smelt vs swelter

smelt

verb
  • To fuse or melt two things into one, especially in order to extract metal from ore; to meld. 

noun
  • Any small anadromous fish of the family Osmeridae, found in the Atlantic and Pacific Oceans and in lakes in North America and northern part of Europe. 

  • Production of metal, especially iron, from ore in a process that involves melting and chemical reduction of metal compounds into purified metal. 

  • Any of the various liquids or semi-molten solids produced and used during the course of such production. 

swelter

verb
  • To perspire greatly from heat. 

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

  • To suffer terribly from intense heat. 

noun
  • Intense heat. 

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