Anatomy . a hollow, pumplike organ of blood circulation, composed mainly of rhythmically contractile smooth muscle, located in the chest between the lungs and slightly to the left and consisting of four chambers

a right atrium that receives blood returning from the body via the superior and inferior vena cavae, a right ventricle that pumps the blood through the pulmonary artery to the lungs for oxygenation, a left atrium that receives the oxygenated blood via the pulmonary veins and passes it through the mitral valve, and a left ventricle that pumps the oxygenated blood, via the aorta, throughout the body.

Zoology .

the homologous structure in other vertebrates, consisting of four chambers in mammals and birds and three chambers in reptiles and amphibians.

the analogous contractile structure in invertebrate animals, as the tubular heart of the spider and earthworm.

the center of the total personality, esp. with reference to intuition, feeling, or emotion

In your heart you know I'm an honest man.

the center of emotion, esp. as contrasted to the head as the center of the intellect

His head told him not to fall in love, but his heart had the final say.

capacity for sympathy; feeling; affection

His heart moved him to help the needy.

spirit, courage, or enthusiasm

His heart sank when he walked into the room and saw their gloomy faces.

the innermost or central part of anything

Notre Dame stands in the very heart of Paris.

the vital or essential part; core

the heart of the matter.

the breast or bosom

to clasp a person to one's heart.

a person (used esp. in expressions of praise or affection)

dear heart.

a conventional shape with rounded sides meeting in a point at the bottom and curving inward to a cusp at the top.

a red figure or pip of this shape on a playing card.

a card of the suit bearing such figures.

hearts,

( used with a singular or plural verb ) the suit so marked

Hearts is trump. Hearts are trump.

( used with a singular verb ) a game in which the players try to avoid taking tricks containing this suit.

Botany . the core of a tree; the solid central part without sap or albumen.

good condition for production, growth, etc., as of land or crops.

Also called core. Ropemaking . a strand running through the center of a rope, the other strands being laid around it.

Archaic .

to fix in the heart.

to encourage. ?

after one's own heart

in keeping with one's taste or preference

There's a man after my own heart!

at heart

in reality; fundamentally; basically

At heart she is a romantic.

break someone's heart, to cause someone great disappointment or sorrow

as to disappoint in love

The news that their son had been arrested broke their hearts.

by heart

by memory; word-for-word

They knew the song by heart.

cross one's heart

to maintain the truth of one's statement; affirm one's integrity

That's exactly what they told me, I cross my heart!

do someone's heart good

to give happiness or pleasure to; delight

It does my heart good to see you again.

eat one's heart out

to have sorrow or longing dominate one's emotions; grieve inconsolably

The children are eating their hearts out over their lost dog.

from the bottom of one's heart, with complete sincerity. Also, from one's heart

from the heart.

have a heart

to be compassionate or merciful

Please have a heart and give her another chance.

have at heart, to have as an object, aim

or desire

to have another's best interests at heart.

have one's heart in one's mouth

to be very anxious or fearful

He wanted to do the courageous thing, but his heart was in his mouth.

have one's heart in the right place, to be fundamentally kind, generous

or well-intentioned

The old gentleman may have a stern manner, but his heart is in the right place.

heart and soul

enthusiastically; fervently; completely

They entered heart and soul into the spirit of the holiday.

in one's heart of hearts

in one's private thoughts or feelings; deep within one

He knew, in his heart of hearts, that the news would be bad.

lose one's heart to

to fall in love with

He lost his heart to the prima ballerina.

near one's heart

of great interest or concern to one

It is a cause that is very near his heart. Also, close to one's heart.

not have the heart

to lack the necessary courage or callousness to do something

No one had the heart to tell him he was through as an actor.

set one's heart against

to be unalterably opposed to

She had set her heart against selling the statue. Also, have one's heart set against.

set one's heart at rest

to dismiss one's anxieties

She couldn't set her heart at rest until she knew he had returned safely.

set one's heart on

to wish for intensely; determine on

She has set her heart on going to Europe after graduation. Also, have one's heart set on.

take heart

to regain one's courage; become heartened

Her son's death was a great blow, but she eventually took heart, convinced that God had willed it.

take or lay to heart

to think seriously about; concern oneself with

He took to heart his father's advice.

to be deeply affected by; grieve over

She was prone to take criticism too much to heart.

to one's heart's content

until one is satisfied; as much or as long as one wishes

The children played in the snow to their heart's content.

wear one's heart on one's sleeve

to make one's intimate feelings or personal affairs known to all

She was not the kind who would wear her heart on her sleeve.

to be liable to fall in love; fall in love easily

How lovely to be young and wear our hearts on our sleeves!

with all one's heart

with earnestness or zeal.

with willingness; cordially

She welcomed the visitors with all her heart.

noun

head , cowardice , fear , exterior , exteriority , outside , periphery , surface

noun

affection , benevolence , character , compassion , concern , disposition , feeling , gusto , humanity , inclination , love , nature , palate , pity , relish , response , sensitivity , sentiment , soul , sympathy , temperament , tenderness , understanding , zest , boldness , bravery , dauntlessness , fortitude , gallantry , guts * , mettle , mind , moxie * , nerve , pluck , purpose , resolution , spirit , spunk * , will , basic , bosom , bottom line * , center , coal and ice , core , crux , focal point , focus , gist , hub , kernel , marrow , middle , nitty-gritty * , nub , nucleus , pith , polestar , quick * , quintessence , root , seat , cardiac organ , clock * , ticker , vascular organ , ticker* , breast , braveness , courageousness , doughtiness , fearlessness , gameness , intrepidity , intrepidness , pluckiness , stoutheartedness , undauntedness , valiance , valiancy , valiantness , valor , essence , meat , stuff , substance , headquarters , bottom , quick , cardia , conscience , interior