Astrology vocabulary begins with the letter D

The partitioning of each Sign into three equal parts of 10 degrees each. Each part is known as a decanate; every Sign is composed of 30 degrees, therefore someone born between the 1st and the 10th day of any sign is said to be born in the First (1st) Decanate. Those born between the 11th and the 20th, the Second Decanate, and those born between the 21st and the last day of any sign are said to have been born in the Third (3rd) Decanate.

Decile (semi-quintile):
An aspect created between two planets, corollary points, or cusps that has an arc of 36°00′.

The arc of measurement in degrees north or south of the celestial equator. The number of degrees a planet is placed vertically from the ecliptic or the horizon. In other words, looking at the night sky, from the horizon, one would look upward to note the position or height of said planet from the horizon to the zenith or topmost part of the sky.

A unit of measurement commonly used in astrology to denote the positions of one sign/planet from another. The Zodiac circle or horoscope consists of a total of 360 degrees, or 12 houses with 30 degrees to each house.

The opposite point from the ascendant; the cusp of the Seventh House. The Descendant describes one person’s interaction with another.

A planet placed in a sign that is opposite to its sign of rulership. This generally causes a lack of synergy. For example, Mercury rules Gemini and is in detriment in Sagittarius.

A Hindu term, also used in Buddhism, which refers to one’s duty or obligations in life. Some believe that this pertains to the Life Purpose, but there is no evidence that this is strictly the case.

Direct Motion:
The normal forward motion of a body through the zodiac signs (Aries, Taurus, Gemini, etc.). This is opposite to retrograde motion, in which a planet moves apparently (but not in actuality), backwards.

Disharmony and Distrust activation:
A turbulent connection which involves Venus and Jupiter and causes disharmony and distrust of one toward the other.