"animal that chews the cud," 1660s, from Latin ruminantem (nominative ruminans), present participle of ruminare "to chew the cud" (see ruminate). As an adjective from 1670s, "ruminating, chewing the cud."
Entries linking to ruminant
ruminate v.
1530s, of a person, "to turn over in the mind, muse, meditate, think again and again;" 1540s, "to chew cud;" from Latin ruminatus, past participle of ruminare "to chew the cud," also "turn over in the mind," from rumen (genitive ruminis) "gullet," a word of uncertain origin. Related: Ruminated; ruminating; ruminative.