do lunch vs eat out

do lunch

verb
  • To have a lunchtime meeting, usually at a restaurant. 

eat out

verb
  • To dine at a restaurant or such public place. 

  • Used other than figuratively or idiomatically: see eat, out. 

  • To erode or encroach upon by gradually consuming. 

  • To perform cunnilingus or anilingus on. 

  • To reprimand severely. 

How often have the words do lunch and eat out occurred in a corpus of books? (source: Google Ngram Viewer )