countersink vs curdle

countersink

verb
  • To cause to sink even with or below the surface. 

  • To create such a conical recess. 

noun
  • a cylindrical recess, typically machined around a hole to admit a screw so that it sits flush with a surface. 

curdle

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

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

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

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