curdle

Etymology

Metathesis of earlier dialectal cruddle, crudle, equivalent to curd + -le (frequentative suffix).

verb

1. (transitive, intransitive) 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. (transitive, intransitive) To clot or coagulate; to cause to congeal, such as through cold. (metaphorically of blood)
   "Vich Ian Vohr," it said, in a voice that made my very blood curdle, "beware of to-morrow!" 1814, Walter Scott, Waverley
3. (transitive) To cause a liquid to spoil and form clumps so that it no longer flows smoothly
   It is enough,' said the agitated Mr. Slurk, pacing to and fro, 'to curdle the ink in one's pen, and induce one to abandon their cause for ever.' 1836, Charles Dickens, The Pickwick Papers