tripe n
1 the stomach lining of an ox, cow, or other ruminant, prepared for cooking
2 Informal something silly; rubbish
3 Archaic, informal intestines; belly
(C13: from Old French, of unknown origin)
rock tripe n (Canadian) any of various edible lichens, esp. of the genus Umbilicaria, that grow on rocks and are used in the North as a survival food