custard vs flan

custard

noun
  • A type of sauce made from milk and eggs (and usually sugar, and sometimes vanilla or other flavourings) and thickened by heat, served hot poured over desserts, as a filling for some pies and cakes, or cold and solidified; also used as a base for some savoury dishes, such as quiches, or eaten as a stand-alone dessert; egg custard. 

  • A similar sauce made from milk and cornflour or custard powder (and usually sugar, and sometimes vanilla or other flavourings) and thickened by heat. 

flan

noun
  • Baked tart with sweet or savoury filling in an open-topped pastry case. (Compare quiche.) 

  • A coin die. (Compare planchet.) 

  • A fan of the U.S. TV series Firefly. 

  • A dessert of congealed custard, often topped with caramel, especially popular in Spanish-speaking countries. 

verb
  • To splay or bevel internally, as a window-pane. 

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