An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

1) General: The angle between one plane and another, or the angle formed by a reference axis and a given line.
2) Binary systems: The angle between the plane of the orbit and the → plane of the sky.
3) Rotating stars: The angle between the → equatorial plane and the → plane of the sky.

→ angle; → inclination.

The angle at which a planet's axis of rotation is tilted, with respect to that of the planet's orbit.

→ axial; → inclination.

1) The angle between two lines or two planes.
2) An orbital element that defines the angle between the orbital plane of a solar system body (planet, comet, asteroid) and the plane of the ecliptic.
3) The angle between the equatorial and orbital planes of a planet.

Inclination, from M.E. inclinacioun, from L. inclination-, from inclinat(us) p.p. of inclinare, from → in- + clinare "to bend;" cf. Gk. klinein "to cause to slope, slant, incline;" Skt. sri- "to lean," O.Pers. θray-; Av. sray- "to lean;" Mod.Pers. kil "bent, inclined, slant;" PIE base *klei- "to lean, incline" from which is also derived P.Gmc. *khlinen (Ger. lehnen, E. lean).

Darkil, from prefix dar- "in" + kil "bent, crooked, inclined" [Dehxodâ], Mid.Pers. xwahl "bent, crooked" (Mod.Pers. dialectal/colloquial variants kowleh, cowleh, cowl, caval, xohl, xohal, hol), cf. Skt. kûla- "slope, declivity;" PIE base *klei-, as above.

The angle between the rotation axis of a planet and the normal to the ecliptic.

→ inclination; → axis.

→ obliquity of the ecliptic.

→ inclination; → Earth; → equator.

Same as → magnetic dip or → dip.

→ magnetic; → inclination.

An → orbital element that defines the angle between the orbital plane of a solar system body (planet, comet, asteroid) and the plane of the ecliptic. The orbital inclination of the Earth's orbit is 0°; those of Mercury, Venus, and Mars are 7.01°, 3.39°, and 1.85° respectively.

→ orbital; → inclination .