noun
rumination
roo-mih-NAY-shun/ˌruːmɪˈneɪʃn/
The repeated chewing of food brought back from the stomach.
Rumination helps cows break down tough grass by chewing it again.

Etymology
The “gullet” root connects this action noun to chewing the cud. Applied to thought, rumination is repeated mental chewing: returning to the same matter and considering it again.
In context
And this is different from rumination, where you tend to settle into the thoughts and brood over them.
More examples
- During rumination, a sheep brings swallowed food back into its mouth.
- The cow rests in the shade during rumination.
- Rumination reduces swallowed plant material to smaller pieces.
Forms
Similar words
- cud chewing
- Names the same process, usually in less technical language.