double date vs roundup

double date

noun
  • A (romantic) date that two couples go on together. 

verb
  • To go on a double date. 

roundup

noun
  • The finishing of an arrangement. 

  • An upward curvature or convexity, as in the deck of a vessel. 

  • The similar police activity of gathering together suspects. 

  • An activity in which cattle are herded together in order to be inspected, counted, branded or shipped. 

  • The forcible gathering together of any particular group of people. 

  • The summary to a news bulletin. 

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