Inclination, n.
Etymology: [L. inclinatio: cf. F. inclination.]
1. The act of inclining, or state of being inclined; a leaning; as, an inclination of the head.
2. A direction or tendency from the true vertical or horizontal direction; as, the inclination of a column, or of a road bed.
3. A tendency towards another body or point
4. (Geom.)
6 more senses
The angle made by two lines or planes; as, the inclination of the plane of the earth's equator to the plane of the ecliptic is about 23º 28'; the inclination of two rays of light.
5. A leaning or tendency of the mind, feelings, preferences, or will; propensity; a disposition more favorable to one thing than to another; favor; desire; love. A mere inclination to a thing is not properly a willing of that thing. South. How dost thou find the inclination of the people Shak.
6. A person or thing loved or admired. Sir W. Temple.
7. (Pharm.)
Decantation, or tipping for pouring. Inclination compass, an inclinometer. -- Inclination of an orbit (Astron.), the angle which the orbit makes the ecliptic. -- Inclination of the needle. See Dip of the needle, under Dip.
Syn. -- Bent; tendency; proneness; bias; proclivity; propensity; prepossession; predilection; attachment; desire; affection; love. See Bent, and cf. Disposition.
Shades of meaning
Fernald has no entry of its own for inclination; he lists it under aim, appetite, attachment, desire, direction, fancy.
Where he writes about it:
Inclination expresses simply a tendency, which may be good or bad, yielded to or overcome; as, an inclination to study; an inclination to drink. — from attachment
Inclination is the mildest of these terms; it is a quiet, or even a vague or unconscious, tendency. — from desire
Even when we speak of a strong or decided inclination we do not express the intensity of desire. — from desire
Course is the direction of a moving object; inclination, that toward which a stationary object leans; tendency, the direction toward which anything stretches or reaches out; tendency is stronger and more active than inclination. — from direction