ETYM Old Eng. bouel, bouele, Old Fren. boel, boele, French boyau, from Latin botellus a small sausage, in Late Lat. also intestine, dim. of Latin botulus sausage.
1. One of the intestines of an animal; an entrail, especially of man; a gut; -- generally used in the plural.
2. Hence, figuratively: The interior part of anything.