To coagulate or concrete; to thicken, or change into curd. Milk curdles by a mixture of runnet.

To thicken; to congeal; as, the blood curdles in the veins.

To change into curd; to cause to thicken, coagulate, or concrete. Runnet or brandy curdles milk. At Florence they curdle their milk with artichoke flowers.

To congeal or thicken. The recital curdled my blood.