from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The membranous sac filled with serous fluid that encloses the heart and the roots of the aorta and other large blood vessels.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A serous membrane that surrounds the heart allowing it to contract.
from the GNU version of the Collaborative International Dictionary of English
- n. The double baglike fold of serous membrane which incloses the heart.
from The Century Dictionary and Cyclopedia
- n. In anatomy and zoology: A somewhat conically shaped membranous sac, inclosing the heart and the origin of the great vessels.
- n. A blood-sinus or special cavity beneath the carapace of a crustacean, in which the heart is suspended by ligaments and arteries, but not otherwise connected.
- n. In mollusks, the spacious dorsal cœlom or body-cavity which is traversed by the contractile vessel which acts like a heart.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a serous membrane with two layers that surrounds the heart
Over at Sterne, Tim has recounted a harrowing turn of events that saw him rushed to hospital and diagnosed with Pericardia, an inflammation of the pericardium, which is the lining of the heart.
The inhabitants, however, always first drink the water in the pericardium, which is described as being best.
The heart is surrounded by a sac called the pericardium.
The pericardium is a sac composed of two layers -- a fibrous membrane on the outside, and a serous one on the inside.
The foramen here described is easily seen; but, as I have stated, there are other modes of communication between the so-called pericardium and the cavity with which the siphuncle communicates, of a far more extensive nature.
The blood, which is a non-corpuscular fluid, is propelled forwards by the contractile dorsal vessel and collected into the central blood-sinus; this lies over the stomochord, and is surrounded on three sides by a closed vesicle, with contractile walls, called the pericardium
It is enclosed with the ascending aorta in a single tube of the visceral layer of the serous pericardium, which is continued upward upon them from the base of the heart.
It may be divided for purposes of description into two parts: an upper portion, above the upper level of the pericardium, which is named the superior mediastinum; and a lower portion, below the upper level of the pericardium.
It is inclosed in a sac, the pericardium, which is composed of a dense fibrous membrane lined by a delicate serous membrane, which is reflected over the heart; the inner layer is firmly adherent to the heart, the outer to the fibrous sac, and there is an intervening space, known as the pericardial space, in which a small amount of serum -- a thin translucent liquid -- is present constantly.
 There is about man's heart a skin called pericardium, containing water, which cools and moistens the heart, lest it should be scorched with continual motion.