D:

Dark Side: those few degrees before a house cusp in which a planet makes its influence felt in the next House as well. A planet 6° to 7° before an angle starts expressing itself through the next angular house. At about 3° to 4° before an angle, a planet’s energy and function belongs somewhat equally to both houses. And at less than 2° before an angle a planet expresses itself predominantly through that next, angular house -- and much less, if at all -- through the house in which it is technically located. (The dark side influence for non-angular houses precedes those houses by only 1° to 3°.) The influence of retrograde planets is only felt if it is significantly closer to the next house cusp: less than 1.5° for fast-moving planets on the dark side of angular cusps, and less than ½° for slow-moving retrograde planets to angular cusps.

So check your chart to see how close your planets are to the end of the house they’re in. If they’re close enough to the end of a house, they should be interpreted as being in, or at least blended with, the next house. For this purpose your birth time must be accurate to within five minutes, as house cusps change 1° to 2° every five minutes of time (the 2° maximum occurs only near the ascendant-descendant axis with Aries rising). If your birth time is expressed as an even hour or half hour, it may be only a guess or approximation and not reliable for these purposes. The same holds true for any aspect of a planet to an angle, and for the degree of a sign on a house cusp. Suppose, for example, you believe that you have 1° of Leo or 28° of Scorpio rising. If your actual time of birth were 5 minutes earlier in the first case or 10 minutes later in the second, you’d have Virgo or Sagittarius respectively rising instead!

Decanate: three sequential 10-degree sections of all signs: the first 10° of any sign is said to be of the nature of the sign itself; the second 10° decanate is of the nature of the next sign of the same element; and the third has the nature of the remaining sign of that element.

Declination: in the equatorial coordinate system, the angle that an object is above or below the Earth’s equator projected on the celestial sphere. This coordinate corresponds to latitude on the Earth. The other coordinate in this system is called "Right Ascension."

Degree: units of angular measure into which a circle or arc can be subdivided for purposes of measuring. The symbol for a degree is °, a superscripted  o. A sign is 1/12th of a 360° circle, or 30°. There are 60 angular minutes (symbol  ') in a degree, 60 angular seconds (symbol  ") in one angular minute, and therefore 3600 seconds in one degree. The Moon and Sun both subtend an arc of ½° in the sky -- which is why they appear to be the same size from Earth and can exactly eclipse each other. Venus at closest approach has an angular diameter of 1', and Uranus has an angular diameter of 3". The closest star in the sky, Alpha Centauri, and the brightest star in the sky, Sirius, both have angular diameters of 0.007".

Descendant: The intersection of the ecliptic with the western horizon where planets set or descend; the beginning of the Seventh house. The Descendant in our chart is our experience of others and the world as not-self; lost aspects of our self that we experience through - or look for in - others, and with which we are least identified.

Detriment: a planet is said to be in its detriment in the sign opposite the one it rules. Here a planet's power is blocked, its full expression hindered, or it has difficulty expressing its positive or optimistic side (in a sign so uncongenial to its nature). The Sun is in its detriment in Aquarius, the Moon in Capricorn, Mercury in Sagittarius or Pisces, Venus in Aries or Scorpio, Mars in Libra or Taurus, Jupiter in Gemini, Saturn in Cancer, Uranus in Leo, Neptune in Virgo, and Pluto in Taurus.

Dignified: said of a planet in a sign it rules. Here it most freely, naturally and powerfully expresses its energy; and, if a personal planet, is a dominant force in the whole chart.

Direct: the apparent forward/clockwise motion of a planet against the background stars as seen from the Earth, as opposed to apparent backward ("retrograde") motion of that same planet seen from the Earth.