dinnertime vs potluck

dinnertime

noun
  • The time when dinner takes place. 

  • The midday break in English schools (some areas), lunchtime. 

potluck

noun
  • A shared meal consisting of whatever guests have brought (sometimes without prior arrangement); a potlatch; also, a dish of food brought to such a meal. 

  • Whatever is available in a particular situation. 

verb
  • To take part in a potluck, where each participant brings a meal to be shared by all. 

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