birdcall vs knell

birdcall

verb
  • To imitate the cry of a bird. 

noun
  • Any vocalisation of a bird. 

  • An imitation of this cry. 

  • A device used to imitate this cry, so as to lure and catch birds. 

knell

verb
  • To signal or proclaim something (especially a death) by ringing a bell. 

  • To ring a bell slowly, especially for a funeral; to toll. 

  • To summon by, or as if by, ringing a bell. 

noun
  • The sound of a bell knelling; a toll (particularly one signalling a death). 

  • A sign of the end or demise of something or someone. 

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