Definition: the part of the zodiac in which in astrology a planet's influence is thought to be least
The opposite of a planet's exaltation is its descension in which the level of its influence is at its lowest. Like exaltation, descension ascends from Middle French and Latin. In Middle French, descension is an astronomical word for the setting, or the descent below the horizon, of a celestial object. The Latinate root, dēscēnsiō, has the same "descent" meaning.
The exaltation is a house where the planet is given more power and freedom to act. The planet is a celebrated guest of honor. The sign opposite a planet’s exaltation was called its fall or descension. The house of its fall was considered a place where a planet is more downtrodden in its significations, like an unwelcome guest.
— Seven Stars Astrology, 6 Sept. 2012
The English noun descent and verb descend trace back to Latin dēscendre, a combination of de- and scendere, which is ultimately from scandēre ("to climb"). In astronomy, the verb indicates movement of a celestial object (such as a constellation or a planet) away from the zenith towards the western horizon. In astrology, it specifies movement of a planet toward its descension.
The brightest and highest is Vega, in the tiny constellation shaped like a parallelogram, called Lyra the harp. Below and left of Vega is Deneb, in Cygnus the swan, and then below and under Cygnus, we can see Altair, in Aquila the eagle. During the summer months this bright asterism will ride up and high near the zenith, and then descend in late summer and all through the fall toward the northwest horizon. Indeed, the Summer Triangle can still be seen low in the northwest sky in the weeks just before Christmas!
— Dennis Herrmann, The Tablot Spy (Easton, Maryland), 4 June 2013
Tebbs said when an astrologer reads a person's chart, many more specific details figure in, including exact time and place of birth, and planets rising or descending at that moment and location.
— Dru Sefton, Newhouse News Service (Washington, D.C.), 2 May 2006