verb

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

   “Too much lemon will curdle the milk in your tea.”

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

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