foster vs lull

foster

verb
  • To nurse or cherish something. 

  • To cultivate and grow something. 

  • To nurture or bring up offspring, or to provide similar parental care to an unrelated child. 

adj
  • Related by such care. 

  • Receiving such care. 

  • Providing parental care to children not related to oneself. 

noun
  • A foster parent. 

  • The care given to another; guardianship. 

lull

verb
  • To cause to rest by soothing influences; to compose; to calm 

  • To become gradually calm; to subside; to cease or abate. 

noun
  • A period of rest or soothing. 

  • A period without waves or wind. 

  • An extended pause between sets of waves. 

  • A period of reduced activity; a respite 

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