Heart

The hollow muscular organ which in vertebrates keeps up the circulation of the blood by rhythmic contraction and dilatation.
The heart as the centre of vital bodily functions; (the seat of) life.
The region of the heart in man; the breast, bosom, chest.
The seat of feeling and thought.
The mind, intellect; especially (the seat of) one’s inmost thoughts and secret feelings; the soul.
(The seat of) perception, understanding, or memory.
(The seat of) the emotions, especially love, as opposed to reason. Frequently contrasted with head.
Susceptibility to emotion; feeling, sensitivity. Also, kindliness, cordiality.
Purpose, inclination, desire.
(The seat of) courage, spirit.
(The source of) energy, enthusiasm, or ardour.
Disposition, temperament, character.
Conscience.
Substituting for the person.
As a term of endearment: a loved one.
A man of courage or spirit.
A central part; a vital or essential part.
The centre, middle, or innermost part of anything.
The part of a time or season when its character is most intense; the height, depths.
A central part of distinct conformation or character.
The vital, essential, or working part of something. Also, the best or most important part.
Vigour, fertility.

Shorter Oxford English Dictionary