ru·men  (rōō'mən)  n. pl. ru·mi·na (-mə-nə) or ru·mens The first division of the stomach of a ruminant animal, in which most food collects immediately after being swallowed and from which it is later returned to the mouth as cud for thorough chewing. Also called paunch. [Latin rūmen, throat.] ru'mi·nal adj. |