A canal giving passage to a hernia: Dr. Small explained that his intestine was pressing against through and causing a bulge in the weakened part of his abdomen creating a hernia canal.

The pouch or protrusion of peritoneum containing a herniated organ or part, formed gradually by pressure against a defect in the containing wall or present at birth: After being examined by Dr. Swift, Marc found out that he had a hernial sac that was causing him so much pain, and that an operation was absolutely necessary.