nadir : The point in the celestial sphere directly opposite the zenith; the point directly beneath an observer on Earth; the low point.

Naibod arc : Mean daily motion of the sun, 59' 08"; used to progress a natal horoscope by assuming one Naibod arc equals one year of life, according to the method introduced by Johann Naibod, sixteenth century astrologer and mathematician.

native : A traditional term that refers to a person for whom a horoscope is erected.

natal astrology : The branch of astrology dealing with the individual. the horoscope cast for the birth time of the individual, showing life potentials, is called a natal horoscope, geniture, radix, or nativity.

nativity : A natal horoscope.

natural chart : A chart with 0° Aries on the cusp of the first house that shows the natural horoscope position of signs. Also called a flat chart.

navamsas : From Hindu astrology, a ninefold division of each sign into 3 1/3° segments, each segment influenced by a sign of the zodiac. The first navamsa of Aries is sub-ruled by Aries, the next by Taurus, and so on, continuing the natural order of the zodiac through the ninth navamsa of Pisces, sub-ruled by Pisces. These "signs within a sign" create variations in interpretation of different degrees of a particular sign.

negative signs : Earth and water signs; an alternate term used to describe "feminine" characteristics of receptivity and passivity. See also feminine signs.

new Moon Lunation : The beginning of a lunation cycle and of the waxing phase. Moon conjunct Sun.

nocturnal : From the Latin nocturnus, of night. Refers to the lower (northern) hemisphere of a horoscope, the "night" section, that part of the heavens that falls below Earth's horizon.

nocturnal arc : The time expressed in right ascension that it takes a planet or degree of the zodiac to move from its setting point on the horizon to its rising point.

nocturnal signs : Signs whose natural positions are in the nocturnal or northern hemisphere of a horoscope: Aries, Taurus, Gemini, Cancer, Leo and Virgo. Also called northern signs.

nodal chart : An equal house chart, which places the Moon's South Node at the Ascendant, used primarily by medical astrologers to diagnose health problems. In this context, the South Node and Ascendant represent the head, the North Node and Decendant the feet, the lower hemisphere the right side of the body and the upper hemisphere the left.

node : The point of intersection of a planet's orbit and the ecliptic.

nonagesimal : The point 90° from the Ascendant. The highest point of the ecliptic above the horizon.

nonile : A ninth harmonic aspect based on division of 360° by 9 (40°). A minor aspect, the nonile is seldom used by modern astrologers. It was once given a fatalistic connotation.

nova : Literally new star; applied to stars that suddenly appear with great brilliance then fade; an exploding star.

oblique ascension : A measurement determined by the angle (ascensional difference) between the point on the celestial equator rising with a planet rising at a point not at the equator.

oblique desension : The angular complement of oblique ascension; i.e., 180° minus the oblique ascension arc.

obliquity of the ecliptic : The angle between the plane of the ecliptic and the plane of the equator. It now measures about 23°27', and is decreasing at the rate of one minute in 128 years.

occidental : Literally western; said of a planet that rises and sets after the Sun.

occidental houses : Correctly, houses that lie in the western (occidental) portion of a horoscope, houses four through nine. Sometimes used to describe first and third quadrant houses (one, two, three, seven, eight and nine), those houses that are moving away from the vertical axis toward the horizon (in a clockwise direction in a horoscope).

occultation : From the Latin occultatio, a hiding; an eclipse of a planet. The term eclipse is usually applied to an occultation that hides the Sun or Moon from Earth's view; occultation describes eclipses that obstruct Earth's view of planets other than the Sun or Moon. The eclipsing planet is emphasized over the occulted (hidden) planet in interpreting the accompanying conjunction between the two planets forming an occultation.

opposition : A second harmonic aspect, separating distance 180°. a major hard aspect, the opposition creates awareness, attraction and antagonism between the planets in polarity.

orb : The number of degrees by which an aspect may vary from partile (exactness) and remain effective.

orbit : The path a heavenly body follows as it travels around another stellar body.

oriental : Literally eastern; said of a planet that rises and sets before the Sun. The oriental planet, called the leading planet, is the one that will rise immediately before the Sun; i.e., the planet that directly precedes the Sun clockwise (behind the Sun in the natural order of the zodiac).

oriental houses : Houses that lie in the eastern (oriental) hemisphere of a horoscope, houses one, two, three, ten, eleven, and twelve. Sometimes used to describe those houses moving away (clockwise) from the horizon (Ascendant-Decendant axis) and toward the vertical axis (meridian axis, MC-IC axis), the second and fourth quadrant houses, namely houses four, five, six, ten, eleven and twelve.

outer houses : Those planets whose orbits fall outside the Asteroid Belt; also called major planets because of their larger orbits. See also major planets.