ruminant

n, adj (animal) that chews the cud, eg a cow 反刍的; 反刍动物（如牛）.

rug, Rugby, Rugby League, Rugby Union, rugged, ruggedly, ruggedness, rugger, ruin, ruination, ruined, ruinous, rule, ruler, ruling, rum, rumba, rumble, rumbling, rumbustious, ruminate, rumination, ruminative, ruminatively, rummage, rummage sale, rummy, rumor, rumour, rumour (US rumor), rumoured (US rumored), rump, rumple, rumpus, rumpus room, run, run (sth) down, run (sth) off, run across, run across (into) sb.(sth.),