Affection, n.
Etymology: [F. affection, L. affectio, fr. afficere. See Affect.]
1. The act of affecting or acting upon; the state of being affected.
2. An attribute; a quality or property; a condition; a bodily state; as, figure, weight, etc. , are affections of bodies. "The affections of quantity." Boyle. And, truly, waking dreams were, more or less, An old and strange affection of the house. Tennyson.
3. Bent of mind; a feeling or natural impulse or natural impulse acting upon and swaying the mind; any emotion; as, the benevolent affections, esteem, gratitude, etc. ; the malevolent affections, hatred, envy, etc.; inclination; disposition; propensity; tendency. Affection is applicable to an unpleasant as well as a pleasant state of the mind, when impressed by any object or quality. Cogan.
4. A settled good will; kind feeling; love; zealous or tender attachment; -- often in the pl. Formerly followed by to, but now more generally by for or towards; as, filial, social, or conjugal affections; to have an affection for or towards children. All his affections are set on his own country. Macaulay.
7 more senses
5. Prejudice; bias. [Obs.] Bp. Aylmer.
6. (Med.)
Disease; morbid symptom; malady; as, a pulmonary affection. Dunglison.
7. The lively representation of any emotion. Wotton.
8. Affectation. [Obs.] "Spruce affection." Shak.
9. Passion; violent emotion. [Obs.] Most wretched man, That to affections does the bridle lend. Spenser.
Syn. -- Attachment; passion; tenderness; fondness; kindness; love; good will. See Attachment; Disease.
Shades of meaning
Fernald has no entry of its own for affection; he lists it under attachment, disease, friendship, love.
Where he writes about it:
Affection expresses more warmth of feeling; we should not speak of a mother's attachment to her babe, but of her affection or of her devotion. — from attachment
Regard is more distant than affection or attachment, but closer and warmer than esteem; we speak of high esteem, kind regard. — from attachment
Disease is the general term for any deviation from health; in a more limited sense it denotes some definite morbid condition; disorder and affection are rather partial and limited; as, a nervous affection; a disorder of the digestive system. — from disease
Friendship is a deep, quiet, enduring affection, founded upon mutual respect and esteem. — from friendship
Friendship is always mutual; there may be unreciprocated affection or attachment, unrequited love, or even unrecognized and unappreciated devotion, but never unreciprocated or unrequited friendship; one may have friendly feelings toward an enemy, but while there is hostility or coldness on one side there can not be friendship between the two. — from friendship
Affection may be purely natural; friendship is a growth. — from friendship
Affection is kindly feeling, deep, tender, and constant, going out to some person or object, being less fervent and ardent than love, whether applied to persons or things. — from love
Love is an intense and absorbing emotion, drawing one toward a person or object and causing one to appreciate, delight in, and crave the presence or possession of the person or object loved, and to desire to please and benefit the person, or to advance the cause, truth, or other object of affection; it is the yearning or outgoing of soul toward something that is regarded as excellent, beautiful, or desirable; love may be briefly defined as strong and absorbing affection for and attraction toward a person or object. — from love