devour vs swallow up

devour

verb
  • To rapidly destroy, engulf, or lay waste. 

  • To take in avidly with the intellect or with one's gaze. 

  • To absorb or engross the mind fully, especially in a destructive manner. 

  • To eat quickly, greedily, hungrily, or ravenously. 

swallow up

verb
  • To voraciously consume resources, such as money; to devour. 

  • To completely enclose or envelop. 

  • To take over or absorb something (especially an organisation) so it no longer has a separate identity; to assimilate. 

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