[Middle English paunche, from Old French panche, from Latin pantex.]
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.
1186, from O.Fr. pance (O.N.Fr. panche) "belly," from L. panticem (nom. pantex) "belly, bowels" (cf. Sp. panza, It. pancia), possibly related to panus "swelling."