celebration vs double date

celebration

noun
  • The observance of a holiday or feast day, as by solemnities. 

  • The act, process of showing appreciation, gratitude and/or remembrance, notably as a social event. 

  • The formal performance of a solemn rite, such as Christian sacrament. 

  • A social gathering for entertainment and fun; a party. 

double date

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

verb
  • To go on a double date. 

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