casserole vs slow cooker

casserole

noun
  • Food that fills the high-walled dish or pan that it was cooked in. 

  • Food, such as a stew, cooked in such a dish. 

  • A dish of glass or earthenware, with a lid, in which food is baked and sometimes served. 

verb
  • To cook like, or as, a casserole; to stew. 

slow cooker

noun
  • A kitchen appliance consisting of a clay pot and its housing with self-contained electrical heating, characterized by a loose-fitting lid, relatively low temperatures, and long cooking times, and used especially in the preparation of stews. 

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