CUD

[noun] [U] - food that has been eaten by an animal with more than one stomach, such as a cow, and that comes back into the animal's mouth to be chewed again before going into the second stomachA cow stood in the middle of the road, calmly chewing the cud.(informal) If you chew the cud, you think slowly and carefully about something.He sat for a moment chewing the cud before he spoke.