CURDLE

Cur″dle (k?r″d'l), v. i. [[From Curd.]] [Sometimes written crudle and cruddle.] 1. 1. To change into curd; to coagulate; as, rennet causes milk to curdle. Thomson.
2. 2. To thicken; to congeal.
Then Mary could feel her heart's blood curdle cold. Southey.