Astrology is the study of the influence that distant cosmic objects, usually stars and planets, have on human lives. Astrology is the study of the correlation between the astronomical positions of the planets and events on earth. A very ancient, but still vital discipline, astrology seeks the meaning and application of the influences of the planets, stars and other celestial phenomena in our lives. Astrology and astronomy have in modern times become separate studies, though for most of human history they were two sides of the same coin.

Absolute Longitude: The degrees of the ecliptic where a planet might be placed according to its sign placement. A Planet at 15 degrees Aries is at 15 degrees Absolute Longitude whereas one at 15 degrees Libra is at 195 degrees Absolute Longitude (Libra being placed at 180 degrees).
Accidental Dignity: When a planet is so placed in the chart that by its house position or relationship with other planets is strengthened.
Ages (e.g. of Aquarius): Time taken for the Vernal Point to move backwards through one sidereal constellation - approx 2,150 years.
Air Signs: Gemini, Libra, and Aquarius.
Altitude: The measurement of a planet in degrees and minutes from the horizon up towards the zenith. It is the planet's angular distance from the horizon measured vertically.
Angle Houses: First, Fourth, Seventh, and Tenth.
Antivertex: Intersection of the Prime Vertical with the ecliptic in the east.
Apogee (apo - away Gaia - Earth): The point in the Moon's orbit that is most distant from the Earth also used when a planet is most distant from the earth.
Apparent Horizon: A plane tangent to earth from a specific location - what we actually see as horizon dividing earth and sky and depending on elevation of the location above seas level.
Apparent Motion: Motion observed from a geocentric position. Motion relative to the earth as if the earth were stationary.
Apparent Solar Time: Measured by the Sun 's apparent motion around the earth. "Sundial Time" or the observable rising of the Sun one day and again the next day.
Application: The movement of a planet toward another planet, cusp, or sensitive point, as an aspect forms between them.
Applying (Aspect): Refers to the relationship of two planets when the faster moving planet in an aspect is in an earlier degree than the slower planet and approaching exactitude.
Arabic Part: Imaginary points in the horoscope that denote various focal points of energy such a good fortune (Part of Fortune), sickness, and marriage.
Arc: Any part of the circumference of a circle in which the distance is measured from one point to another or, astrologically the distance travelled along the ECLIPTIC by a body over a given period of time.
Ascendant: The exact degree of the Zodiac coming over the eastern horizon at the particular True Local Time you took you first breath at the Geocentric Latitude of the locale. It is the rising sign at the threshold gate to your first house and dominates your personality and how others perceive you.
Ascending Node: where the Moon crosses the Ecliptic from South to North.
Aspects: Zodiac angles between planets or points in your horoscope that are within specific degrees of each other also create relationships with each other that have significant impact, both positive and negative, upon your emotions, mind, body, and spirit. Some major aspects included trine, square, opposition, conjunction, and sextile.

Bary Centre: The point corresponding to the centre of mass of the planets in the solar system, which the planets orbit. The Bary Centre is normally close to the centre of the Sun.

Cardinal Signs: Aries, Cancer, Libra, Capricorn.
Cusp: The line of division between two houses.

Decanate: One of three divisions of a Sun Sign ( 0º-9º59', 10º-19º59', 20º-29º59').
Declination: The manner of indicating distance N. or S. of the Celestial Equator. The maximum possible declination of the Sun is 23° 28' which occurs at the Solstices, when the Sun passes the Tropics (0°) of Cancer and Capricorn, the limit of the pole's greatest inclination from the plane of the Earth's orbit. The first degrees of Aries and Libra have no declination, since at these points the ecliptic intersects the equator. However, planets at this longitude may have declination.
Descendant: The cusp between the sixth and seventh houses, the point at which the western horizon intercepts the ecliptic.

Earth Signs: Taurus, Virgo, and Capricorn.
Ecliptic: The plane of the Earth's orbit as it sweeps around the Sun.
Ephemeris: A book of astrological compilations containing the daily movements of the Sun, the Moon, and the planets.

Fire Signs: Aries, Leo, Sagittarius.
Fixed Signs: Taurus, Leo, Scorpio, and Aquarius.
Forecast: When an astrologer analyzes planetary movements and how they impact your chart in order to make recommendations about courses of action..

Geocentric: Geocentric means viewed from the centre of the earth. The Geocentric co-ordinate system is the most commonly used system in astrology
Glyphs: Symbols used to represent the Sun Signs, planets, and aspects.

Hemispheric Divisions: Half-circles of the horoscope wheel when it is divided by the Meridian (Midheaven/Nadir axis) or the Horizon (Ascendant/Descendant axis).
Horoscope: A detailed map or chart of the heavens and planets overhead at the exact time and place of birth that covers the full sky circle of 360º. A birth chart acts as a blueprint of a person's life.
Houses: One of twelve divisions made in the cycle of the Earth's daily rotation. Each house represents specific areas of activity in an individual's life. The seventh house, for instance rules marriage and partnerships, as well as, open enemies and lawsuits.

Imum Coeli (IC): The Imum Coeli is the point where the Lower Meridian intersects the Ecliptic. The Imum Coeli is opposite the Midheaven (MC). In most house systems the IC forms the 4th House Cusp. In interpretation, it represents the personal foundations, source of being, origins, roots, beginnings of life in the womb, personal, family and tribal heritage; connection with home; parental influence; most private and least conscious area.

Joys: The planets are said to rejoice in certain houses. A planet in its joy is good for the planet, but not necessarily of advantage to the native. The joys of the planets are as follows: Mercury - 1st House; Moon - 3rd House; Venus - 5th House; Mars - 6th House; Sun - 9th House; Jupiter - 11th House & Saturn - 12th House..

Kronos: Kronos is one of the eight hypothetical planets (also called the Transneptunian planets or TNPs) of the Hamburg School. Interpretations for Kronos include things that are above average, things that are high up, such as mountains, aeroplanes, government authorities.

Lunations: A Lunation is one Lunar cycle of a New Moon to the next New Moon. The New Moon occurs when the Moon is conjunct the Sun. The interval from one New Moon to the next is 29 days, 12 hours, 44 minutes and 2.8 seconds and is called the Synodic Month..

Meridian: A great circle or imaginary line on the celestial sphere that passes through the northern horizon and southern zenith directly above the observer
Midheaven: The doorway into the tenth house in an astrological chart. It is the highest point in the chart, and, it indicates the way in which each person is spiritually connected to his or her Higher Self and the spiraling circle dance of life.
Mutable Signs: Gemini, Virgo, and Sagittarius.

Nadir (IC): The point directly opposite the Midheaven (MC). As the doorway on the cusp of the fourth house, it represents your spiritual foundation.
Nodes: The north and south nodes are two points where a planet's orbit intersects the ecliptic. The nodes of the Moon are especially significant. Your Moon's north node is a positive area of your life, a repository for undiscovered talents that promotes emotional, psychological, and spiritual growth. Your Moon's south node represents unfulfilling old habits, thoughts, activities and belief systems you need to discard in order to grow.

Obliquity: Obliquity is the angle made between the plane of the ecliptic and the plane of the celestial equator. This value is currently around 23 degrees 26 minutes and varies slowly over the centuries.

Part of Fortune: An area of your life such as art or healing where you excel naturally. It is an area where you find happiness and peace as you express these innate abilities.
Planets: The Sun, Moon, Mercury, Venus, Mars and other planetary bodies that are placed in different houses in your horoscope and influence your daily life. Uranus, for instance, is a planet that focalizes swift transformation, heightened perceptions, spiritual responsibility, and transcendent perspectives.

Quadruplicity: Each sign belongs to one of four groups of signs based on their elemental tendencies to be either fiery, earthy, airy, or watery in temperament.

Retrograde: When a planet appears to move backwards, it is moving retrograde. It is a time of treading water when you can feel stuck and stymied by delays.
Right Ascension: Distance measured along the celestial equator, Eastward from the point of the Spring Equinox; or, as sometimes described, distance along the circle of declination.
Rising Sign: The Sign or the subdivision of the Sign which was rising on the eastern horizon at the moment of birth, is deemed to exercise a strong influence upon the personality and physical appearance of the native. This is subject to modification by virtue of concurrent aspects. The placement of the Lord of the Ascendant, of the Moon, or of the planet aspecting the ascending degree, are also deemed to accent the particular subdivision of the Rising Sun in which the ascending degree falls. Interpretations by numerous authorities are available by Signs, by Decans and by demi-Decans - both incorrectly termed Faces by some authorities. In applying any of the interpretations attached to a Rising Sign it should be remembered that the presence of a planet in the Ascendant will always modify the influence of the Sign itself.

Stellium: A cluster of four or more planets in the birth chart.
Sun Signs: The twelve traditional signs of the Zodiac (Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces). During twelve portions of the year (about 30 days each), the Sun passes through each sign.

Transits: An Ephemeris records the daily movements of the planets across the sky. These transits impact your natal chart and influence your mind, body, and spirit. Study and scrutiny of theses transits can contribute to personal growth and give you a heads up about approaching successes, as well as, stresses.
Triplicity: Each sign belongs to one of three groups of signs based on its intrinsic characteristic of being - either cardinal (initiatory), fixed (stable), or mutable (adaptable) in nature.

Universal Time: Mean Solar Time calculated from mean 0 hours on the Greenwich Meridian.

Vernal Equinox: The intersection of the celestial equator with the ecliptic plane each solar year at 0º Aries. The Sun crosses the celestial equator moving from north to south.
Vertex: The Vertex is the intersection of the Ecliptic with Western Prime Vertical.

Watchers of the Heavens: Applied by the Persians (c. 3000 B.C.) to the four Royal Stars then at the angles of the Zodiac: the Watcher of the East, then at the Vernal Equinox - Aldebaran; the Watcher of the North, which then marked the Summer Solstice - Regulus; the Watcher of the West, then at the Autumnal Equinox - Antares, the Watcher of the South, which then marked the Winter Solstice - Fomalhaut.
Water Signs: Cancer, Scorpio, and Pisces.
Weak Signs: Cancer, Capricorn and Pisces.
Whole Signs: Gemini, Libra and Aquarius, and by some authorities Taurus.

Year: The Solar or Tropical Year is the period of time in which the earth performs a revolution in its orbit about the Sun, or passes from any point of the ecliptic to the same point again. It consists of 365.2422 days, or 365d 5h 48M 46s. (The Sun's motion in longitude in a Julian year of 365.25 days is 360° 27'7.)

The Sidereal Year is a period of 365d.256 or 365d 6h 9m 9s.5, during which time the Sun's center, departing eastward from the ecliptic meridian of a given star, returns to the same; an astral year. It is about 20 minutes longer than the tropical year. The sidereal month is of a duration of 27d.322. The Anomalistic Year, that between two successive perihelion passages of the Earth, is 365d.26, or 4m 43s.5 longer than the sidereal year, although it is increasing in length even faster than the sidereal year. v. Day.

Zenith (MC): The point in the celestial sphere that is directly overhead an observer at a particular location on the Earth's surface.
Zodiac: The division of the heavens into twelve astrology signs, each comprising exactly one-twelfth of the heavenly circle or 30º and totalling 360º.