ruminant

A mammal of suborder Ruminantia, comprising the traguloids (chevrotains) and pecorans (other deer, giraffes, and Bovidae), and suborder Tylopoda (the camel family); an artiodactyl; many-chambered stomach breaks down coarse plant material; camels and chevrotains have three chambers; pecorans have four - the rumen (or paunch), reticulum (or honeycomb bag), omasum (manyplies, or psalterium), and abomasum (or reed); swallows much food quickly, then moves to a place of safety where it regurgitates mouthfuls (cud), chews them thoroughly, then reswallows; also known as a cud-chewer.

A ruminant is any hooved animal that digests its food in two steps, first by eating the raw material and regurgitating a semi-digested form known as cud, then eating the cud, a process called ruminating.