curdle vs ice over

curdle

verb
  • To clot or coagulate; to cause to congeal, such as through cold. (metaphorically of blood) 

  • To form curds so that it no longer flows smoothly; to cause to form such curds. (usually said of milk) 

  • To cause a liquid to spoil and form clumps so that it no longer flows smoothly 

ice over

verb
  • To become covered in ice, usually of a body of water. 

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