foster vs wait on

foster

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

  • To cultivate and grow something. 

  • To nurse or cherish something. 

noun
  • A foster parent. 

  • The care given to another; guardianship. 

adj
  • Related by such care. 

  • Receiving such care. 

  • Providing parental care to children not related to oneself. 

wait on

verb
  • To provide a service to (someone); to act as a servant to (someone); to serve (someone) as a waiter or waitress in a restaurant. 

  • To wait for (a person). 

  • To wait for (a thing, or an event to take place). 

  • To fly above its master, waiting till game is sprung. 

  • To be in store for (someone). 

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