Heart
Definition of Heart:
A hollow muscular organ which receives the blood from the veins and propels it into the arteries. It is divided by a musculomembranous septum into two halves -- right or venous and left or arterial -- each of which consists of a receiving chamber (atrium) and an ejecting chamber (ventricle). (NCI)

A hollow organ located slightly to the left of the middle portion of the chest. It is composed of muscle and it is divided by a septum into two sides: the right side which receives de-oxygenated blood from the body and the left side which sends newly oxygenated blood to the body. Each side is composed of two chambers: the atrium (receiving blood) and ventricle (ejecting blood).
Heart is part of the Organ group
Heart is also know as:
Cardiac