rumination

Rumination, in zoology, refers to the process by which ruminant animals, such as cattle, sheep, and deer, digest plant material. These mammals have a specialized, multi-chambered stomach that allows them to break down tough cellulose found in grasses and foliage, which they cannot digest directly.1

The process involves regurgitating partially digested food, known as cud, from the first stomach chamber (the rumen) back into the mouth for a second chewing. This cud is then swallowed again and passed through the other stomach chambers (reticulum, omasum, and abomasum) where it is further digested with the help of microorganisms. This unique digestive system enables herbivores to extract nutrients from fibrous plant matter. The term "ruminate" also extends metaphorically to deep, meditative thought.1234