(1) The physiologic process in ruminant animals in which coarse, hastily eaten food is regurgitated from the rumen, thoroughly rechewed, reduced to finer particles, mixed with saliva, and reswallowed. (2) A disorder of infancy characterized by repeated regurgitation of food, with weight loss or failure to thrive, developing after a period of normal functioning. (3) Periodic reconsideration of the same subject. [L. ruminatio, fr. rumino, to chew the cud, think over, fr. rumen, throat]