(Heb. yothe'reth; i.e., "something redundant"), the membrane which covers the upper part of the liver (Exodus 29:13,22; Leviticus 3:4,10,15; 4:9; 7:4; marg., "midriff"). In Hosea 13:8 (Heb. seghor; i.e., "an enclosure") the pericardium, or parts about the heart, is meant.
These dictionary topics are from M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition, published by Thomas Nelson, 1897. Public Domain, copy freely.
Easton, Matthew George. "Entry for 'Caul'". "Easton's Bible Dictionary".