Churchill is probably getting at the distinction between Germanic and Latinate root words in English. Hemingway used to write with a obvious preference for Germanic root words, which were short and tough and had a pleasing sound. Latinate root words are usually long ten-cent words lacking the same utilitarian grace of their Germanic root analogs.

I always thought it would be a fun project to use an etymology database to make a Latinate-to-Germanic thesaurus, something you could use just like spell check on a document to suggest Germanic alternatives to Latinate words.