allay vs soften

allay

verb
  • To alleviate; to abate; to mitigate. 

  • To make quiet or put at rest; to pacify or appease; to quell; to calm. 

noun
  • Alleviation; abatement; check. 

soften

verb
  • To make less harsh 

  • To make something soft or softer. 

  • To palatalize. 

  • To become or make (a consonant) more lenis, to lenite. 

  • To become soft or softer 

  • To undermine the morale of someone (often soften up). 

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